J.L. Gracia, E. O'Riordan, Singularly perturbed reaction-diffusion problems with discontinuities in the initial and/or the boundary data. Accepted in J. Comput. Appl. Math.

J.L. Gracia, E. O'Riordan, M. Stynes, Convergence analysis of a finite difference scheme for a two-point boundary value problem with a Riemann-Liouville-Caputo fractional derivative. Accepted in BIT Numerical Mathematics.

J.L. Gracia, E. O'Riordan, Numerical methods for singularly perturbed parabolic problems with incompatible boundary-initial data in two space dimensions. Accepted in proceedings of BAIL18 (Lecture Notes in Computational Science and Engineering).

J.L. Gracia, E. O'Riordan, Parameter-uniform numerical methods for singularly perturbed parabolic problems with incompatible boundary-initial data, Appl. Numer. Math. 146 (2019) 436-451.

C. Clavero, J.L. Gracia, Uniformly convergent additive schemes for 2D singularly perturbed parabolic systems of reaction-diffusion type, Numer. Algorithms 80 (2019) 1097-1120.

J. Fernandez-Pato, J.L. Gracia, P. Garcia-Navarro, A fractional-order infiltration model to improve the simulation of rainfall/runoff in combination with a 2D shallow water model, J. Hydroinform 20 (2018) 898-916.

J.L. Gracia, E. O'Riordan, M. Stynes, A fitted scheme for a Caputo initial-boundary value problem, J. Sci. Comput. 76 (2018) 583-609.

J.L. Gracia, E. O'Riordan, M. Stynes, Convergence in positive time for a finite difference method applied to  a fractional convection-diffusion equation. Comput. Methods Appl. Math. 18 (2018) 33-42.(special issue on ``Numerical analysis of fractional differential equation").

J.L. Gracia, E. O'Riordan, Singularly perturbed initial-boundary value problems with a pulse in the initial condition. Proceedings of the International Conference on Boundary and Interior Layers - Computational and Asymptotic Methods, BAIL 2016, Beijing (China), August 2016, Z. Huang, M. Stynes, Z. Zhang (Eds.). Lecture Notes in Comput. Sci. Engineering 120, Springer, 87-99, 2017.

M. Stynes, J.L. Gracia, Preprocessing schemes for fractional-derivative problems to improve their convergence rates, Appl. Math. Letters 74 (2017), 187-192.

J.L. Gracia, E. O'Riordan, A singularly perturbed convection-diffusion problem with a moving pulse, J. Comput. Appl. Math. 321 (2017) 371-388.

M. Stynes, E. O'Riordan, J.L. Gracia, Error analysis of a finite difference method on graded meshes for a time-fractional diffusion equation, SIAM J. Numer. Anal. 55 (2017) 1057-1079.

J.L. Gracia, N. Madden, T.A. Nhan, Applying a patched mesh method to efficiently solve a singularly perturbed reaction-diffusion problem, Modeling, Simulation and Optimization of Complex Processes, HPSC 2015 : Proceedings of the Sixth International Conference on High Performance Scientific Computing, Springer, 41-53, 2017.

J.L. Gracia, E. O'Riordan, M. Stynes, Convergence outside the initial layer for a numerical method for the time-fractional heat equation, Lecture Notes in Comput. Sci., Springer, 2017, 80-91 (proceedings NAA'16, Lozenetz, Bulgaria).

C. Clavero, J.L. Gracia, G.I. Shishkin, L.P. Shishkina, An efficient numerical scheme for 1D parabolic singularly perturbed problems with an interior and boundary layers, J. Comp. Appl. Math. 318 (2017) 634-645 (proceedings CMMSE 2015).

M. Stynes, E. O'Riordan, J.L. Gracia, Necessary conditions for convergence of difference schemes for fractional-derivative two-point boundary value problems, BIT 56 (2016) 1455-1477.

J.L. Gracia, E. O'Riordan, Numerical approximation of solution derivatives of singularly perturbed parabolic problems of convection-diffusion type, Math. Comp. 85, (2016) 581-599.

J.L. Gracia, M. Stynes, Boundary layers in a Riemann-Liouville fractional derivative two-point boundary value problem, Lecture Notes in Comput. Sci. Engineering 87-98, 108, Springer, 2015 (proceedings BAIL 2014).

M. Stynes, J.L. Gracia, Blow-up of solutions and interior layers in a Caputo two-point boundary value problem, Lecture Notes in Comput.Sci. Engineering 293-302, 108, Springer, 2015 (proceedings BAIL 2014).

C. Clavero, J.L. Gracia, G.I. Shishkin, L.P. Shishkina, Schemes convergent $\varepsilon$-uniformly for 1D parabolic singularly perturbed problems with a degenerating convective term and a discontinuous source, Math. Model. Anal. 20 (2015) 641-657.

J.L. Gracia, E. O'Riordan, Scaled discrete derivatives of singularly perturbed elliptic problems, Numer. Methods Partial Differ. Equ. 31 (2015) 225-252.

M. Stynes, J.L. Gracia, A finite difference method for a two-point boundary value problem with a Caputo fractional derivative, IMA J. Numer. Anal. 35 (2015) 698-721.

J.L.Gracia, M.Stynes, Formal consistency versus actual convergence rates of difference schemes for fractional-derivative boundary value problems, Fract. Calc. Appl. Anal. 18 (2015) 419-436.

M. Stynes, J.L. Gracia, Boundary layers in a two-point boundary value problem with a Caputo fractional derivative, Comput. Methods Appl. Math. 15 (2015) 79-95.

J.L. Gracia, M. Stynes, Central difference approximation of convection in Caputo fractional derivative two-point boundary value problems, J. Comput. Math. Appl. 273 (2015) 103-115.

J.L. Gracia, E. O'Riordan, Numerical approximation of solution derivatives in the case of singularly perturbed time dependent reaction-diffusion problems, J. Comp. Appl. Math. 273 (2015) 13-24.

C. Clavero, J.L. Gracia, An improved uniformly convergent scheme in space for 1D parabolic reaction-diffusion systems, Appl. Math. Comp. 243 (2014) 57-73.

C. Clavero, J.L. Gracia, Uniformly convergent additive finite difference schemes for singularly perturbed parabolic reaction-diffusion systems, Comput. Math. Appl. 67 (2014) 655-670.

G.I. Shishkin, L. Shishkina, J.L. Gracia, C. Clavero, On a numerical technique to study difference schemes for singularly perturbed parabolic reaction-diffusion equations, Int. J. Numer. Anal. Mod. 11 412-426, 2014 (special issue in honour to the 65th birthday of Prof. Francisco Lisbona).

J.L. Gracia, E. O'Riordan, Interior layers in a singularly perturbed time dependent convection-diffusion problem, Int. J. Numer. Anal. Mod. 11 358-371, 2014 (special issue in honour to the 65th birthday of Prof. Francisco Lisbona)

J.L. Gracia, E. O'Riordan, A singularly perturbed reaction-diffusion problem with a discontinuity between the boundary and initial data. I. Dimov, I. Faragó, and L. Vulkov (Eds.): Proceedings NAA Conference 2012, Lectures Notes in Computer Science, 8236, 303-310, 2013.

C. Clavero, J.L. Gracia, A high order uniformly convergent method with Richardson extrapolation in time for singularly perturbed reaction-diffusion parabolic problems, J. Comp. Appl. Math. 252 (2013) 75-–85.

C. Clavero, J.L. Gracia, G.I. Shishkin, L.P. Shishkina, Grid approximation of a singularly perturbed parabolic equation with degenerating convective term and discontinuous right-hand side, Int. J. Numer. Anal. Mod. 10 (2013) 795-814.

C. Clavero, J.L. Gracia, G.I. Shishkin, L.P. Shishkina, A robust numerical method for a singularly perturbed parabolic convection-diffusion problem with a degenerating convective term and a discontinuous right-hand side. Proceedings of ENUMATH 2011, Computational Science and Engineering, Springer, 2013, 257-266.

J.L. Gracia, E. O'Riordan, A singularly perturbed parabolic problem with a layer in the initial condition, Appl. Math. Comp. 219 (2012) 498-510.

J.L. Gracia, E. O'Riordan, A singularly perturbed time dependent convection diffusion problem with an interior layer, Int. J. Numer. Anal. Mod. 9 (2012) 823-843.

C. Clavero, J.L. Gracia, G.I. Shishkin, L.P. Shishkina, Numerical experiments for a singularly perturbed parabolic problem with degenerating convective term and discontinuous source, Comput. Math. Appl. Math. 2 2012, 139-152 (special issue dedicated to the 60th birthday of Martin Stynes).

C. Clavero, J.L. Gracia, A high order HODIE finite difference scheme for 1D parabolic singularly perturbed reaction-diffusion problems, Appl. Math. Comp. 218 (2012) 5067-5080.

C. Clavero, J.L. Gracia, M. Stynes, A simpler analysis of a hybrid numerical method for time-dependent convection-diffusion problems, J. Comp. Appl. Math. 235 (2011) 5240-5248.

C. Clavero, J.L. Gracia, Uniformly convergent finite difference schemes for singularly perturbed 1D parabolic reaction-diffusion problems. Proceedings BAIL, 2010, C. Clavero, J.L. Gracia, F.J. Lisbona (Eds.), Lecture Notes in Comput. Sci. Engineering, 81, Springer, 2011, 75-83.

J.L. Gracia, E. O'Riordan, A singularly perturbed convection diffusion parabolic problem with an interior layer. Proceedings BAIL, 2010, C. Clavero, J.L. Gracia, F.J. Lisbona (Eds.), Lecture Notes in Comput. Sci. Engineering, 81, Springer, 2011, 139-146.

C. Clavero, J.L. Gracia, On the uniform convergence of a finite difference scheme for time dependent singularly perturbed reaction-diffusion problems, Appl. Math. Comp. 216 (2010) 1478-1488.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona, C. Rodrigo, Multigrid finite element methods on semi-structured triangular grids for planar elasticity, Numer. Linear Algebr. Appl. 17 (2010) 473-493.

C. Clavero, J.L. Gracia, F.J. Lisbona, An almost third order finite difference scheme for singularly perturbed reaction-diffusion systems, J. Comp. Appl. Math.J. 234 (2010) 2501-2515.

C. Clavero, J.L. Gracia, F.J. Lisbona, Second order uniform approximations for the solution of time dependent singularly perturbed reaction-diffusion systems, Int. J. Numer. Anal. Mod. 7 (2010) 428-443.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona, C. Rodrigo, "Efficient geometric multigrid implementation for triangular grids", J. Comp. Appl. Math.234 (Proceedings ICCAM08) (2010) 1027-1035.

J.L. Gracia, F.J. Lisbona, E. O'Riordan, "A coupled system of singularly perturbed parabolic reaction-diffusion equations", Adv. Comput. Math. 32 (2010) 43-61.

C. Clavero, J.L. Gracia, F.J. Lisbona, High order schemes for reaction-diffusion singularly perturbed systems, Proceedings BAIL 2008, A. Hegarty, N. Kopteva, E. O' Riordan, M. Stynes (Eds.), Lecture Notes in Comput. Sci. Engineering, 69, Springer, 2009, 107-115.

J.L. Gracia, F.J. Lisbona, M. Madaune-Tort, E. O' Riordan, A system of singularly perturbed semilinear equations, Proceedings BAIL 2008, A. Hegarty, N. Kopteva, E. O' Riordan, M. Stynes (Eds.), Lecture Notes in Comput. Sci. Engineering, 69, Springer, 2009, 163-172.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona. "Fourier analysis for multigrid methods on triangular grids", SIAM J. Sci. Comput. 31 (2009) 2081-2102.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona, C. Rodrigo, "On geometric multigrid methods for triangular grids using three-coarsening strategy", Appl. Numer. Math. 59 (2009) 1693-1708.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona and C.W. Oosterlee, "Distributive Smoothers in Multigrid for Problems with Dominating Grad-Div Operators", Numer. Linear Algebr. Appl. 15 (2008) 661-683.

F.J Gaspar, J.L. Gracia, F.J. Lisbona and P.N. Vabishchevich, "A stabilized method for a secondary consolidation Biot's model", Numer. Methods Partial Differ. Equ. 24 (2008) 60-78.

B. Bujanda, C. Clavero, J.L. Gracia and J.C. Jorge, "A High Order Uniformly Convergent Alternating Direction Scheme for Time Dependent Reaction-Diffusion Singularly Perturbed Problems'', Numer. Math. 107 (2007) 1-25.

J.L. Gracia and F. Lisbona, "A uniformly convergent scheme for a system of reaction-diffusion equations", J. Comp. Appl. Math. 206 (2007) 1-16.

J.L. Gracia and E. O'Riordan, "A Defect-Correction Parameter-Uniform Numerical Method for a Singularly Perturbed Convection-Diffusion Problem in One Dimension", Numer. Algorithms 41 (2006) 359-385

J.L. Gracia, E. O'Riordan and M. Pickett, "A Parameter Robust Second Order Numerical Method for a Singularly Perturbed Two-Parameter Problem", Appl. Numer. Math. 56 (2006) 962-980.

J.L. Gracia and C. Clavero, "A Compact Finite Difference Scheme for 2D Reaction Diffusion Singularly Perturbed Problems'', J. Comp. Appl. Math. 192 (2006) 152-167.

C. Clavero, J.L. Gracia and J.C. Jorge, "A Uniformly Convergent Alternating Direction HODIE Finite Difference Scheme for 2D Time Dependent Convection Diffusion Problems", IMA J. Numer. Anal. 26 (2006) 155-172.

C. Clavero and J.L. Gracia, "High Order Methods for Elliptic and Time Dependent Reaction-Diffusion Singularly Perturbed Problems", Appl. Math. Comp. 168 (2005) 1109-1127.

C. Clavero, J.L. Gracia and E. O'Riordan, "A Parameter Robust Numerical Method for a Two Dimensional Reaction-Diffusion Problem'', Math. Comp., 74 (2005) 1743-1758.

C. Clavero, J.L. Gracia and J.C. Jorge, "Second Order Numerical Methods for One Dimensional Parabolic Singularly Perturbed Problems with Regular Layers", Numer. Methods Partial Differ. Equ.21 (2005) 149-169.

C. Clavero and J.L. Gracia, "HODIE Finite Difference Schemes on Generalized Shishkin Meshes", J. Comp. Appl. Math. 164-165 (2004) 195-206.

J.L. Gracia, J.C. Jorge, B. Bujanda and C. Clavero, "High Order Uniformly Convergent Fractional Step RK Methods and HODIE Finite Difference Schemes for 2D Evolutionary Convection-Diffusion Problems", Journal of Computational Methods in Sciences and Engineering 3 (2003) 403-413.

C. Clavero, J.L. Gracia, F. Lisbona and G.I. Shishkin, "A Robust Method of Improved Order for Convection-Diffusion Problems in Domain with Characteristic Boundaries", ZAMM, 82 (2002) 631-647.

J.L. Gracia, F. Lisbona and C. Clavero, "High Order $\varepsilon$-Uniform Methods for a Singularly Perturbed Reaction-Diffusion Problems". L. Vulkov, J. Wasniewski, P. Yalamov (eds): Numerical Analysis and it's Applications NAA/2000: Second International Conference (Bulgaria, 2000), Lecture Notes in Computer Science, Springer-Verlag, 1988 (2001) 350-358.

C. Clavero, J.L. Gracia and F. Lisbona, "High Order Methods on Shishkin Meshes for Singular Perturbation Problems of Convection-Diffusion Type", Numer. Algorithms, 22 (1999) 73-97.

J.L. Gracia, E. O'Riordan, Singularly perturbed reaction-diffusion problems with discontinuities in the initial and/or the boundary data. 16th Annual Workshop on Numerical Methods for Problems with Layer Phenomena. Sevilla (Spain), February 2019.

J.L. Gracia, E. O'Riordan, M. Stynes, Numerical approximation of a space-fractional differential equation. Congreso Bienal de la RSME. Santander (Spain), February 2019.

J.L. Gracia, E. O'Riordan, M. Stynes, A two-point boundary value problem with a Caputo fractional derivative, 2nd Fractional Calculus Meeting, Madrid (Spain), November 2018.

J.L. Gracia, E. O'Riordan, M. Stynes, A collocation method for a two-point boundary value problem with a Riemann-Liouville-Caputo fractional derivative. Proceedings of Conference Zaragoza-Pau on Mathematics and its Applications, September 2018. Monografías del Seminario Matemático García de Galdeano, 2019, 42, pp 111-125.

J.L. Gracia, E. O'Riordan, Parameter-uniform global accuracy for singularly perturbed parabolic problems with incompatible boundary-initial data, International Conference BAIL 2018 Boundary and Interior Layers, Glasgow (Scotland), June 2018.

J.L. Gracia, Aproximación con un esquema de diferencias finitas de la ecuación de difusión fraccionaria en tiempo, I Jornadas de Cálculo Fraccionario. Instituto de Matemáticas Interdisciplinar. Universidad Complutense de Madrid (Spain), 13-14 November 2017.

J.L. Gracia, E. O'Riordan, M. Stynes, A time-fractional differential equation with a Caputo derivative: Regularity of the solution and convergence analysis of a finite difference scheme, Congreso Bienal de la Real Sociedad de Matemática Aplicada, Zaragoza (Spain), February, 2017.

J.L. Gracia, E. O'Riordan, M. Stynes, On the convergence of a finite difference scheme for a time fractional-diffusion equation, Fourteenth International Conference Zaragoza-Pau on Mathematics and its Applications, Jaca (Spain), September 2016. (Numerical approximation of a time fractional-derivative initial-boundary value problem with boundary layers, Proceedings of the conference: Monografías Matemáticas García de Galdeano, 41, 95-105, 2018).

J.L. Gracia, E. O'Riordan, Singularly perturbed initial-boundary value problems with a pulse in the initial condition, International Conference BAIL 2016 Boundary and Interior Layers BAIL, Beijing (China), August 2016.

J.L. Gracia, M.Stynes, Boundary layers in a two-point boundary value problem with fractional derivatives. Third Workshop on Fractional Calculus, Probability and Non-Local Operators: Applications and Recent Developments, Bilbao (Spain). November 2015.

J.L. Gracia, M.Stynes, Boundary layers in a Caputo fractional derivative problem II, International Conference BAIL 2014 Boundary and Interior Layers BAIL, Prague (Czech Republic), September 2014.

J.L. Gracia, M.Stynes, Finite difference methods for a two-point boundary value problem with a Caputo fractional derivative, International Conference on Fractional Differentiation and Its Applications, ICFDA'14, Catania (Italy), 23-26 June 2014.

J.L. Gracia, M.Stynes, Analysis of a finite difference method for a fractional-derivative two-point boundary value problem, Fractional Calculus, Probability and Non-local Operators: Applications and Recent Developments. A workshop on the occasion of the retirement of Francesco Mainardi, Bilbao (Spain), 2013.

J.L. Gracia, E. O'Riordan, On the uniform convergence of singularly perturbed reaction-diffusion problems with non-smooth data, Twelfth International Conference Zaragoza-Pau on Applied Mathematics and Statistics. Jaca (Spain), 2012. M.C. López de Silanes, M. Palacios, G. Sanz, É. Ahusborde, C. Amrouche (eds.), Monografías Matemáticas del Seminario García de Galdeano, 2014, 39, 121-131

C. Clavero, J.L. Gracia, An analysis of the uniform convergence of a finite difference scheme for parabolic reaction-diffusion systems splitting the time and space discretizations, Workshop Numerical Methods for Ordinary and Partial Differential Equations and Applications (dedicated to the 65th birthday of Prof. Francisco Lisbona), Zaragoza (Spain), 2012.

J.L. Gracia, E. O'Riordan, A singularly perturbed reaction-diffusion problem with a discontinuity between the boundary and initial data, Fifth Conference on Numerical Analysis and Applications, Lozenetz (Bulgaria), 2012.

J.L. Gracia, E. O'Riordan, On the global convergence of a singularly perturbed parabolic problem of reaction diffusion type with a discontinuous initial condition", Workshop Numerical Analysis for Singularly Perturbed Problems (dedicated to the 60th birthday of Prof. Martin Stynes), Dresden (Germany), 2011.

C. Clavero, J.L. Gracia, Time and space-accurate numerical solution of one-dimensional parabolic singularly perturbed problems of reaction-diffusion type, 24th Biennial Conference on Numerical Analysis, Glasgow (Scotland), 2011.

J.L. Gracia, E. O'Riordan, A singularly perturbed time dependent reaction-diffusion problem with a regularized discontinuous initial condition, Progress on Difference Equations. Dublin (Ireland), 2011.

J.L. Gracia, E. O'Riordan, Singularly perturbed 1D parabolic convection-diffusion problems with an interior layer, 9th Annual Workshop on Numerical Methods for Problems with Layer Phenomena. Dublin (Ireland), 2011.

J.L. Gracia, C. Clavero, Uniformly convergent finite difference schemes for singularly perturbed 1D parabolic reaction-diffusion problems, International Conference BAIL 2010. Zaragoza (Spain), 2010.

C. Clavero, J.L. Gracia, On the uniform convergence of a finite difference scheme for time dependent singularly perturbed reaction-diffusion problems, 8th Annual Workshop on Numerical Methods for problems with Layer Phenomena. Limerick (Ireland), 2010.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona, C. Rodrigo, "Local Fourier analysis on triangular grids". Ninth European MultiGrid Conference. Bad Herrenalb (Germany), 2008.

J.L. Gracia, F.J. Lisbona, M. Madaune-Tort and E. O'Riordan, "A system of singularly perturbed semilinear equations". International Conference BAIL 2008 Boundary and Interior Layers - Computational and Asymptotic Methods. Limerick (Ireland), 2008.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona and C. Rodrigo, "Geometric multigrid methods for non-rectangular grids". 13th International Congress on Computational and Applied Mathematics, Ghent (Belgium), 2008.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona and C. Rodrigo, "On geometric multigrid methods for triangular grids using three-coarsening strategy". 13th International Conference Mathematical Modelling and Analysis and Third International Conference Approximation Methods and Orthogonal Expansions. Tartu (Estonia), 2008.

J.L. Gracia and F. Lisbona, "A priori meshes for singularly perturbed reaction-diffusion systems". First French-Spanish Congress of Mathematics. Zaragoza (Spain), 2007.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona and P.N. Vabishchevich, "Staggered Grids for the Discretization of the Secondary Consolidation Biot's Model". Third International Conference Computational Methods in Applied Mathematics. Minsk (Belarus), 2007.

J.L. Gracia and F.J. Lisbona, "A first order uniformly convergent scheme for a system of two coupled equations of reaction-diffusion type". 5th Annual Workshop on Numerical Methods for Problems with Layer Phenomena Limerick (Ireland), 2006.

C. Clavero, J.L. Gracia and E. O'Riordan, "The Defect-Correction Technique Applied to Singularly Perturbed Elliptic Problems of Convection-Diffusion Type". Ninth International Conference Zaragoza-Pau on Applied Mathematics and Statistics. Jaca (Spain), 2005. Monografías del Seminario Matemático García de Galdeano, 33 (2006) 411-418.

B. Bujanda, C. Clavero, J.L. Gracia and J.C. Jorge, "A HODIE Alternating Direction Scheme for a 2D Reaction-Diffusion Singularly Perturbed Problem". 10th International Conference Mathematical Modelling and Analysis and 2nd International Conference Computational Methods in Applied Mathematics. Trakai (Lithuania), 2005.

J.L. Gracia, E. O'Riordan and M.L. Pickett, "A Second Order Finite Difference Scheme for Singularly Perturbed Two-Parameter Problems". 4th Annual Workshop on Numerical Methods for Problems with Layer Phenomena. Limerick (Ireland), 2005.

C. Clavero and J.L. Gracia, "A High Order HOC Finite Difference Schemes for 2D Reaction-Diffusion Singularly Perturbed Problems''. International Conference on Computational and Mathematical Methods in Science and Engineering (CMMSE-2004). Uppsala (Sweden), 2004. E. Brändas, J. Vigo-Aguiar (eds): Proceedings of CMMSE 2004, 49-52.

S. Natesan, J.L. Gracia and C. Clavero, "Singularly Perturbed Boundary--Value Problems With Two Small Parameters - A Defect Correction Approach''. International Conference on Boundary and Interior Layers (BAIL 2004). Toulouse (France), 2004

C. Clavero and J.L. Gracia, "Some Methods of Order Three for Reaction-Diffusion Problems". First International Conference on Computational Methods in Applied Mathematics (CMAM-I 2003). Minsk (Belarus), 2003.

J.L. Gracia and C. Clavero, "El Método de Schwarz para Problemas Singularmente Perturbados de Reacción-Difusión". XVIII CEDYA / VIII CMA. Tarragona (Spain), 2003. Electronic proceeding. (In Spanish)

J.L. Gracia, J.C. Jorge, B. Bujanda and C. Clavero, "High Order Uniformly Convergent Fractional Step RK Methods and HODIE Finite Difference Schemes for 2D Evolutionary Convection-Diffusion Problems". International Conference on Computational and Mathematical Methods in Science and Engineering (CMMSE 2002). Alicante (Spain), 2002. J. Vigo-Aguiar, B.A Wade (eds): Proceedings CMMSE, vol I (2002) 149-158.

J.L. Gracia and C. Clavero, "Convergencia Uniforme de Orden Alto con Interpolación sobre Mallas de Shishkin". XVII CEDYA / VII CMA. Salamanca (Spain), 2001. Electronic proceeding. (In Spanish)

C. Clavero and J.L. Gracia, "A HODIE Method for 2D Parabolic Problems of Convection-Diffusion Type". VII Jornadas de Zaragoza-Pau de Matemática Aplicada y Estadística. Jaca (Spain), 2001. M. Madaune-Tort, D. Trujillo, M.C. López de Silanes, M. Palacios, G. Sanz (eds.), Monográfias del Seminario Matemático García de Galdeano, 27 (2003) 217-224.

J.L. Gracia, F. Lisbona and C. Clavero, "High Order Uniform Methods for Singularly Perturbed Reaction-Diffusion Problems". Second Conference on Numerical Analysis and Applications. Rousse (Bulgary), 2000.

J.L. Gracia, F. Lisbona and C. Clavero, "Un Método Uniformemente Convergente sobre Mallas de Shishkin para un Problema Elíptico con Capas Límite Regular y Parabólicas". XVI CEDYA / VI CMA. Las Palmas de Gran Canaria (Spain), 1999. R. Montenegro, G. Montero, G. Winter (eds.), Universidad de Las Palmas de Gran Canaria, vol. II (1999) 1157-1164. (In Spanish)

J.L. Gracia, C. Clavero and F. Lisbona, "Aproximación Numérica de Problemas de Convección-Difusión, usando un Esquema Upwind Mejorado sobre una Malla de Shishkin". VI Jornadas de Zaragoza-Pau de Matemática Aplicada y Estadística. Jaca (Spain), 1999. Publications of l'Université de Pau et des Pays de l'Adour (2001) 289-296.

J.L. Gracia, C. Clavero and F. Lisbona, "Un Método de Orden 3 para Problemas Lineales de Perturbación Singular de Tipo Reacción-Difusión". IV Congreso de Métodos Numéricos en Ingeniería. Sevilla (Spain), 1999. Electronic proceeding. (In Spanish)

C. Clavero and J.L. Gracia, "Convergencia Uniforme de un Esquema Clásico sobre Mallados de Shishkin para un Problema de Convección Difusión". XV CEDYA / V CMA. Vigo (Spain), 1997 . Colecc. Congr. No 9, University of Vigo, vol. I (1998) 237-242. (In Spanish)

J.L Gracia, E. O'Riordan Interior layers in singularly perturbed parabolic problems, International conference “Actual problems of mathematical physics". Dedicated to the 95th anniversary of A. G. Sveshnikov and the 80th anniversary of V. F. Butuzov. Moscow (Russia), November 27-30, 2019.

E. O'Riordan, J.L. Gracia, Singularly perturbed reaction-diffusion problems with incompatible boundary-initial data, International Conference BAIL 2018 Boundary and Interior Layers, Glasgow (Scotland), June 2018.

E. O'Riordan, J.L. Gracia, Parameter-uniform numerical/analytical method for a problem with incompatible boundary-initial data, 15th Annual Workshop on Numerical Methods for Problems with Layer Phenomena, Larnaca (Cyprus) May 2018.

J. Fernandez-Pato, J.L. Gracia, P. Garcia-Navarro, Modelling infiltration in 2D distributed hydraulic simulations using fractional spatial derivatives, Workshop on Fluid Mechanics, Tarragona (Spain), July 2017.

J. Fernandez-Pato, J.L. Gracia, P. Garcia-Navarro, Aplicacion de las derivadas fraccionarias a la simulacion hidogeologica, Congress on Numerical Methods on Engineering (SEMNI), Valencia (Spain), July 2017.

J.L. Gracia, E. O'Riordan, M. Stynes, A graded-mesh finite difference scheme for a time-fractional diffusion equation, 27th Biennial Conference on Numerical Analysis, Glasgow (Scotland), June, 2017.

C. Clavero, J.L. Gracia, An efficient numerical method for 2D systems of singularly perturbed parabolic reaction-diffusion equations, International Conference on Computational and Mathematical Methods in Science and Engineering (CMMSE), Rota (Spain), July, 2017. Proceedings of the conference.

J.L. Gracia, E. O'Riordan, M. Stynes, Error analysis of a finite difference method on graded meshes for a time-fractional diffusion equation, Workshop on Numerical Methods for Fractional-derivative Problems: Singularities and Fast Algorithms, Beijing (China), 19-20 May, 2017.

M. Stynes, E. O'Riordan, J.L. Gracia, A finite difference method on graded meshes for a time-fractional diffusion equation, Mathematical Methods for Applications: ANZIAM-ZPAMS Joint Conference, Hangzhou (China), November 11-14th 2016.

C. Clavero, J.L Gracia, Efficient numerical methods for coupled singularly perturbed systems of reaction-diffusion type, Fourteenth International Conference Zaragoza-Pau on Mathematics and its Applications, Jaca (Spain). September 2016. Proceedings of the conference: Monografías Matemáticas García de Galdeano, 41, 63-74, 2018.

D. Irisarri, J.L. Gracia, Numerical approximation of singularly perturbed reaction-diffusion problems with the virtual element method, Fourteenth International Conference Zaragoza-Pau on Mathematics and its Applications, Jaca (Spain). September 2016. Proceedings of the conference: Monografías Matemáticas García de Galdenao, 41, 85-94, 2018..

M. Stynes, E. O'Riordan, J.L. Gracia, Regularity of time-fractional reaction-diffusion problems and their solution by a graded-mesh finite difference method, Sixth Conference on Numerical Analysis and Applications (NAA'16), Lozenetz (Bulgary). June 2016.

M. Stynes, E. O'Riordan, J.L. Gracia, Graded-mesh convergence of a finite difference method for a time-fractional reaction-diffusion problem. International Conference on Applied Mathematics, Hong Kong (China). May 2016.

M. Stynes, E. O'Riordan, J.L. Gracia, Error analysis of a finite difference method on graded meshes for a time-fractional diffusion equation, 13th Annual Workshop on Numerical Methods for Problems with Layer Phenomena, Moscow (Russia). April 2016.

M.Stynes, J.L. Gracia, E. O'Riordan, Analysis of a finite difference method for a time-fractional advection-diffusion equation. Workshop Flow in Deformable Porous Media, Zaragoza (Spain). November 2015.

C. Clavero, J.L. Gracia, G.I. Shishkin, L. Shishkina, A uniformly convergent method for a two parameter parabolic singularly perturbed problem with interior layers. 15th International Conference Computational and Mathematical Methods in Science and Engineering. (CMMSE 2015). Cadiz (Spain), July 2015. Proceedings conference, Ed. J. Vigo-Aguiar et al, (2015) 332-341.

J.L. Gracia, N. Madden, T.A. Nhan, Applying a patched mesh method to efficiently solve a singularly perturbed reaction-diffusion problem, 6th International Conference on Modeling, Simulation and Optimization of Complex Processes, Hanoi (Vietnam), March 2015.

M.Stynes, J.L. Gracia, Boundary layers in a Caputo fractional derivative problem I, International Conference BAIL 2014 Boundary and Interior Layers BAIL, Prague (Czech Republic), September 2014.

C. Clavero, J.L. Gracia, A high order in space uniformly convergent method for parabolic singularly perturbed reaction-diffusion systems, 14th CMMSE, Cadiz (Spain), 2014.

M.Stynes, J.L. Gracia, Boundary layers in a fractional-derivative boundary value problem, 11th Annual Workshop on Numerical Methods for Problems with Layer Phenomena, Novi-Sad (Serbia), 2014.

J.L. Gracia, E. O'Riordan, Pointwise accuracy of numerical approximations to the scaled partial derivatives of the solutions to singularly perturbed elliptic problems, 25th Biennial Conference on Numerical Analysis, Glasgow (Scotland), 2013.

L. Shishkina, G.I. Shishkin, J.L. Gracia, Numerical studying fractional errors of $\varepsilon$-uniformly convergent schemes for parabolic reaction-diffusion equations, Eighteenth International Conference MMA and Fourth International Conference AMOE, Tartu (Estonia), 2013.

J.L. Gracia, E. O'Riordan, Discrete approximations to the scaled partial derivatives of the solutions to singularly perturbed parabolic problems Tenth Annual Workshop on Numerical Methods for Problems with Layer Phenomena, Larnaca (Cyprus), 2013.

J.L. Gracia, E. O'Riordan, Interior layers in a singularly perturbed time dependent convection-diffusion problem, Workshop Numerical Methods for Ordinary and Partial Differential Equations and Applications (dedicated to the 65th birthday of Prof. Francisco Lisbona), Zaragoza (Spain), 2012.

J.L. Gracia, C. Clavero, G. Shishkin, L. Shishkina, Interior layers for a 1D parabolic convection-diffusion problem with a discontinuous source term, 17th International Conference on Mathematical Modelling and Analysis (MMA2012), 2012, Tallinn (Estonia).

C. Clavero, J.L. Gracia, F. Lisbona, Uniform convergence of the Crank-Nicolson and central differences scheme for 1D parabolic singularly perturbed reaction-diffusion problems, 12th International Conference Computational and Mathematical Methods in Science and Engineering, La Manga -Murcia (Spain). Proceedings conference, Ed. J. Vigo-Aguiar, 318-328, 2012.

C. Clavero, J.L. Gracia, G.I. Shishkin, L.P. Shishkina, Some results for singularly perturbed problems with discontinuous data and interior layers: uniform convergence on special meshes", Workshop Numerical Analysis for Singularly Perturbed Problems (dedicated to the 60th birthday of Prof. Martin Stynes), Dresden (Germany), 2011.

J.L. Gracia, E. O'Riordan, Numerical approximation of a singularly perturbed parabolic problem with a regularized initial condition, European Numerical Mathematics and Advanced Applications (ENUMATH), Leicester (United Kingdom), 2011.

C. Clavero, J.L. Gracia, G.I. Shishkin, L.P. Shishkina, A uniformly convergent method for a time-dependent convection-diffusion singularly perturbed problem with a degenerating convective term and a discontinuous right-hand side, European Numerical Mathematics and Advanced Applications (ENUMATH), Leicester (United Kingdom), 2011.

C. Clavero, J.L. Gracia, "A uniformly convergent hybrid scheme for one dimensional time-dependent reaction--diffusion problems", Eleventh International Conference Computational and Mathematical Methods in Science and Engineering. Alicante (Spain), 2011.

C. Clavero, J.L. Gracia, F. Lisbona, "Uniformly convergent methods for singularly perturbed problems of convection-diffusion and reaction-diffusion type", Eleventh International Conference Zaragoza-Pau on Applied Mathematics and Statistics. Jaca (Spain), 2010.

J.L. Gracia, E. O'Riordan,"A singularly perturbed time dependent convection diffusion problem with an interior layer", International Conference BAIL 2010. Zaragoza (Spain), 2010.

J.L. Gracia, E. O'Riordan,"Interior layers in singularly perturbed time dependent problems", 8th Annual Workshop on Numerical Methods for problems with Layer Phenomena. Limerick (Ireland), 2010.

C. Clavero, J.L. Gracia, F. Lisbona, "Efficient numerical solutions for linear singularly perturbed coupled systems in the reaction terms", XXI CEDYA / XI CMA. Ciudad Real (Spain), 2009.

C. Rodrigo, F.J. Gaspar, J.L. Gracia, F.J. Lisbona, Multigrid finite element methods on semi-structured triangular grids, XXI CEDYA / XI CMA. Ciudad Real (Spain), 2009.

C. Clavero, J.L. Gracia, F.J. Lisbona, "High order finite difference schemes for linear elliptic singularly perturbed coupled systems". 23rd Biennial Conference on Numerical Analysis. Glasgow (Scotland), 2009.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona, C. Rodrigo, "Vector Fourier analysis on triangular grids for planar elasticity". Fourteenth Cooper Mountain Conference on Multigrid Methods. Colorado (USA), 2009.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona, C. Rodrigo, "Design of geometric multigrid methods on semi-structured grids". Fourteenth Cooper Mountain Conference on Multigrid Methods. Colorado (USA), 2009.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona, C. Rodrigo, "Geometric multigrid methods on triangular grids". Ninth European MultiGrid Conference. Bad Herrenalb (Germany), 2008.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona, C. Rodrigo, "Geometric multigrid methods on triangular grids". International workshop Numerical Analysis and Scientific Computing, Rostov-on-Don (Rusia), 2008.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona and C. Rodrigo, "Development of efficient geometric multigrid algorithms by LFA for systems of partial differential equations on triangular grids". Tenth International Conference Zaragoza-Pau on Applied Mathematics and Statistics. Jaca (Spain), 2008. M. Madaune-Tort, D. Trujillo, M.C. López de Silanes, M. Palacios, G. Sanz, J.J. Torrens (eds.), Monografías del Seminario Matemático García de Galdeano, 2010, 35, 145-153.

C. Clavero, J.L. Gracia and F. Lisbona, "High order schemes for reaction-diffusion singularly perturbed coupled systems". International Conference BAIL 2008 Boundary and Interior Layers - Computational and Asymptotic Methods. Limerick (Ireland), 2008.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona and C.W. Oosterlee, "Distributive Smoothers in Multigrid for Dominating Grad-Div Problems". 13th International Congress on Computational and Applied Mathematics, Ghent (Belgium), 2008.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona and C. Rodrigo, "Geometric multigrid methods for systems of partial differential equations on triangular grids". 13th International Conference Mathematical Modelling and Analysis and Third International Conference Approximation Methods and Orthogonal Expansions. Tartu (Estonia), 2008.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona and C.W. Oosterlee, "Distributive smoother for dominating grad-div problems". 13th International Conference Mathematical Modelling and Analysis and Third International Conference Approximation Methods and Orthogonal Expansions. Tartu (Estonia), 2008.

F. Gaspar, J.L. Gracia, F. Lisbona and C.W. Oosterlee, "Finite difference approximation for secondary consolidation problems and its numerical resolution by multigrid". XX CEDYA / X CMA. Sevilla (Spain), 2007.

C. Clavero, J.L. Gracia, F. Lisbona and C. Rodrigo, "Efficient resolution of singularly perturbed coupled systems: Equations of reaction-diffusion". XX CEDYA / X CMA. Sevilla (Spain), 2007.

F.J. Gaspar, J.L. Gracia, F.J. Lisbona and P.N. Vabishchevich, "A multigrid algorithm for finite difference discretizations on triangular grids". Third International Conference Computational Methods in Applied Mathematics. Minsk (Belarus), 2007.

C. Clavero, J.L. Gracia and F.J. Lisbona, "A second order uniform convergent method for a singularly perturbed parabolic system of reaction--diffusion type''. International Conference on Boundary and Interior Layers (BAIL 2006). Göttingen (Germany).

C. Clavero and J.L. Gracia, "Richardson extrapolation on a Shishkin mesh for reaction-diffusion singularly perturbed problems". XIX CEDYA / IX CMA. Leganés (Spain), 2005.

J.L. Gracia and E. O'Riordan, "A Defect-Correction Method for a Convection-Diffusion Problem in One Dimension". 4th Annual Workshop on Numerical Methods for Problems with Layer Phenomena. Limerick (Ireland), 2005.

C. Clavero and J.L. Gracia, "A HOC Finite Difference Scheme to Solve 2D Elliptic Reaction-Diffusion Problems". 4th Annual Workshop on Numerical Methods for Problems with Layer Phenomena. Limerick (Ireland), 2005.

C. Clavero and J.L. Gracia, "Richardson Extrapolation on Generalized Shishkin Meshes for Singularly Perturbed Problems". VIII Jornadas de Zaragoza-Pau de Matemática Aplicada y Estadística. Jaca (Spain), 2003. Monografías del Seminario Matemático García de Galdeando, 31 (2004) 169-178.

C. Clavero and J.L. Gracia, "HODIE Finite Difference Schemes and the Richardson Extrapolation on Generalized Shishkin Meshes". Tenth International Congress on Computational and Applied Mathematics (ICCAM 2002). Leuven (Belgium), 2002.

C. Clavero, J.L. Gracia and J.C. Jorge, "A Numerical Method of Second Order in Space and Time for 1D Parabolic Singularly Perturbed problems". Workshop Numerical Methods for Singular Perturbation, Oberwolfach (Germany), 2001.

C. Clavero and J.L. Gracia, "Finite Difference Methods of High Order on Shishkin Meshes". Workshop Numerical Methods for Singular Perturbation, Oberwolfach (Germany), 1998.