FAZULLIN, Z.Yu.; KANGUZHIN, B.E.; SEITOVA, A.A. Stable perturbations of boundary problems for differential equations. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 92, n. 4, p. 38–43, 2018. DOI: 10.31489/2018m4/38-43. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/237. Acesso em: 2 jul. 2025.