KOPACH, M.I.; OBSHTA, A.F.; SHUVAR, B.A. An application of analogues of two-sided Kurpel’s methods to ordinary differential equations. Carpathian Mathematical Publications, [S. l.], v. 2, n. 2, p. 48–54, 2010. Disponível em: https://journals.pnu.edu.ua/index.php/cmp/article/view/3966. Acesso em: 19 jun. 2024.