ORUMBAYEVA, N. T.; SABITBEKOVA, G. A boundary value problem for nonlinear differential equation with arbitrary functions. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 85, n. 1, p. 71–76, 2017. DOI: 10.31489/2017m1/71-76. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/148. Acesso em: 10 jul. 2025.