SURAGAN, Durvudkhan; SABITBEK, Bolys. The 15th International ISAAC Congress. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 113, n. 1, p. 221–222, 2024. Disponível em: http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/699. Acesso em: 22 jul. 2025.