SULEIMBEKOVA, A.O. Separability of the third-order differential operator given on the whole plane. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 105, n. 1, p. 109–117, 2022. DOI: 10.31489/2022m1/109-117. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/485. Acesso em: 1 sep. 2025.