[1] Babu, A.R. and Ramanujam, N. The SDFEM for singularly perturbed convection-diffusion problems with discontinuous source term arising in the chemical reactor theory, Int. J. Comput. Math. 88(8) (2011), 1664–1680.
[2] Brdar, M. and Zarin, H. A singularly perturbed problem with two param-eters on a Bakhvalov-type mesh, J. Comput. Appl. Math. 292(1) (2016), 307–319.
[3] Cen, Z. A hybrid difference scheme for a singularly perturbed convection-diffusion problem with discontinuous convection coefficient, Appl. Math. Comput. 169(1) (2005), 689–699.
[4] Das, P. and Mehrmann, V. Numerical solution of singularly perturbed convection-diffusion-reaction problems with two small parameters, BIT Numer. Math. 56(1) (2016), 51–76.
[5] Kadalbajoo, M.K. and Yadaw, A.S. Parameter-uniform Ritz-Galerkin finite element method for two parameter singularly perturbed boundary value problems, Int. J. Pure Appl. Math. 55(2) (2009), 287–300.
[6] Linß, T. Layer-adapted meshes for reaction-convection-diffusion prob-lems, Springer, 2009.
[7] Linß, T. and Roos, H.G. Analysis of a finite-difference scheme for a singularly perturbed problem with two small parameters, J. Math. Anal. Appl. 289(2) (2004), 355–366.
[8] Ranjan, K.R. and Gowrisankar, S. Uniformly convergent NIPG method for singularly perturbed convection diffusion problem on Shishkin type meshes, Appl. Numer. Math. 179(4) (2022); 125–148.
[9] Ranjan, K.R. and Gowrisankar, S. NIPG method on Shishkin mesh for singularly perturbed convection–diffusion problem with discontinuous source term, Int. J. Comput. Methods 20(2) (2023), 2250048.
[10] Roos, H.G. and Zarin, H. The streamline-diffusion method for a convection–diffusion problem with a point source, J. Comput. Appl. Math. 150(1) (2003), 109–128.
[11] Singh, G. and Natesan, S. Study of the NIPG method for two–parameter singular perturbation problems on several layer adapted grids, J. Appl. Math. Comput. 63(1) (2020), 683–705.
[12] Zarin, H. Exponentially graded mesh for a singularly perturbed problem with two small parameters, Appl. Numer. Math. 120 (2017), 233–242.
[13] Zhang, J., Ma, X. and Lv, Y. Finite element method on Shishkin mesh for a singularly perturbed problem with an interior layer, Appl. Math. Lett. 121 (2021), 107509.
[14] Zhu, P. and Xie, S. Higher order uniformly convergent continu-ous/discontinuous Galerkin methods for singularly perturbed problems of convection-diffusion type, Appl. Numer. Math. 76 (2014), 48–59.
[15] Zhu, P., Yang, Y. and Yin, Y. Higher order uniformly convergent NIPG methods for 1-D singularly perturbed problems of convection-diffusion type, Appl. Math. Model. 39(22) (2015), 6806–6816.