IL’KIV, V.S.; SAVKA, I.Ya.; SYMOTYUK, M.M. Sobolev periodic solutions of a partial differential equation with coefficients which depend on a parameter. Carpathian Mathematical Publications, [S. l.], v. 5, n. 2, p. 249–255, 2013. DOI: 10.15330/cmp.5.2.249-255. Disponível em: https://journals.pnu.edu.ua/index.php/cmp/article/view/1316. Acesso em: 20 apr. 2024.