ELAZZOUZI, A.; EZZINBI, K.; KRICHE, M. On the periodic solutions for some retarded partial differential equations by the use of semi-Fredholm operators. CUBO, A Mathematical Journal, [S. l.], v. 23, n. 3, p. 469–487, 2021. DOI: 10.4067/S0719-06462021000300469. Disponível em: https://cubo.ufro.cl/ojs/index.php/cubo/article/view/2855. Acesso em: 24 apr. 2024.