ASRAT, T.; FILE, G.; AGA, T. Fourth-order stable central difference method for self-adjoint singular perturbation problems. Ethiopian Journal of Science and Technology, [S. l.], v. 9, n. 1, p. 53–68, 2025. Disponível em: https://journals.bdu.edu.et/index.php/EJST/article/view/2035. Acesso em: 4 feb. 2026.