[1] J.J.H. Miller, R.E. O'Riordan, G.I. Shishkin, Fitted Numerical Methods for Singular Perturbation Problems. World Scientific, Singapore, 1996.
[2] H.-G. Roos, M. Stynes, L. Tobiska, Robust Numerical Methods for Singularly Perturbed Differential Equations, Springer-Verlag, Berlin, Heidelberg, 2008.
[3] S. Natesan, N. Ramanujam, An asymptotic-numerical method for singularly perturbed Robin problems-I, Appl. Math. Comput. 126 (2002) 97-107.
[4] Z.-D. Cen, H.-Y. Gao, Uniform convergence analysis of a singularly perturbed Robin problem on a Bakhvalov-Shishkin mesh, J. Zhejiang Univ. (Science Edition) 31 (2004) 373-375 (in Chinese).
[5] R.B. Kellogg, A. Tsan, Analysis of some difference approximations for a singular perturbation problem without turning points, Math. Comput. 32 (1978) 1025-1039.
[6] A.S. Bakhvalov, On the optimization of methods for solving boundary value problems in the presence of boundary layers, Zh. Vychisl. Mat. Mat. Fiz. 9(1969) 841-859 (in Russian).
[7] G.I. Shishkin, Grid approximation of singularly perturbed elliptic and parabolic equations, Second doctorial thesis, Keldysh Institute, Moscow, 1990 (in Russian).
[8] T. Linβ, An upwind difference scheme on a novel Shishkin-type mesh for a linear convection-diffusion problem, J. Comput. Appl. Math. 110 (1999) 93-104.
[9] M. Stynes, H.-G. Roos, The midpoint upwind scheme, Appl. Numer. Math. 23 (1997) 361-374.