OMAROVA, B.; SARTABANOV, Z. On Multiperiodic Solutions of Perturbed Nonlinear Autonomous Systems with the Differentiation Operator on a Vector Field. Eurasian Mathematical Journal, [S. l.], v. 12, n. 1, 2024. Disponível em: https://emj.enu.kz/index.php/main/article/view/206. Acesso em: 5 oct. 2024.