RAGULA, K.; SOUJANYA, G.B.S.L. Numerical Scheme for Singularly Perturbed Differential Equations with Small Shifts Using Non-Polynomial Quartic Spline. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 121, n. 1, p. 217–227, 2026. DOI: 10.31489/2026m1/217-227. Disponível em: https://mts.buketov.edu.kz/mathematics-vestnik/article/view/792. Acesso em: 4 apr. 2026.