[10]. S. Kumar, Sumit & S. Kumar (2025). A high-order adaptive numerical method for boundary layer-originated nonlinear problems with non-local boundary condition. International Journal of Applied Nonlinear Science.

[9]. C. Clavero, S. Kumar, & S. Kumar (2025). A priori and a posteriori error estimates for efficient numerical schemes for coupled systems of linear and nonlinear singularly perturbed initial-value problems. Applied Numerical Mathematics, 208, 123-147, Part B.

[8]. S. Kumar, S. Kumar, & P. Das (2025). Second-order a priori and a posteriori error estimations for integral boundary value problems of nonlinear singularly perturbed parameterized form. Numerical Algorithms, 99, 1365-1392.

[7]. S. Kumar, S. Kumar, H. Ramos & K. Kuldeep (2024). A parameter uniform numerical method on a Bakhvalov type mesh for singularly perturbed degenerate parabolic convection-diffusion problems. Journal of Applied Mathematics and Computing, 70, 5645-5668.

[6]. S. Kumar, S. Kumar, & Sumit (2024). A priori and a posteriori error estimation for singularly perturbed delay integro-differential equations. Numerical Algorithms, 95(4), 1561-1582.

[5]. S. Kumar, S. Kumar, & Sumit (2024). High‐order convergent methods for singularly perturbed quasilinear problems with integral boundary conditions. Mathematical Methods in the Applied Sciences, 47(13), 11106-11119.

[4]. A. Jaiswal, S. Kumar, & S. Kumar (2023). A priori and a posteriori error analysis for a system of singularly perturbed Volterra integro-differential equations. Computational and Applied Mathematics, 42(6):278.

[3]. Sumit, S. Kumar, & S. Kumar (2022). A high-order convergent adaptive numerical method for singularly perturbed nonlinear systems. Computational and Applied Mathematics, 41(2):83.

[2]. S. Kumar, S. Kumar, & Sumit (2022). A posteriori error estimation for quasilinear singularly perturbed problems with integral boundary condition. Numerical Algorithms, 89, 791–809.

[1]. M. Devakar, A. Raje, & S. Kumar (2018). Numerical study on an unsteady flow of an immiscible micropolar fluid sandwiched between Newtonian fluids through a channel. Journal of Applied Mechanics and Technical Physics, 59, 980–991.

• S. C. S. Rao and S. Kumar. Grid equidistribution-based numerical approach for time-dependent singularly perturbed reaction-diffusion problems with large delay. (Under Review in Numerical Functional Analysis & Optimization)

• S. C. S. Rao and S. Kumar. A parameter uniform grid equidistribution method for time-dependent singularly perturbed reaction-diffusion problems with large delay. (communicated)

• S. Kumar and S. C. S. Rao. A second-order uniformly convergent scheme for singularly perturbed Volterra integro-differential equations. (Communicated) 

1. S. Kumar (2023). A priori and a posteriori error estimates for singularly perturbed differential and integro-differential equations.