AGARWAL, R. P.; FILIPPAKIS, M. E.; O‘REGAN, D.; PAPAGEORGIOU, N. S. Multiple Solutions for Doubly Resonant Elliptic Problems Using Critical Groups. CUBO, A Mathematical Journal, [S. l.], v. 10, n. 3, p. 21–41, 2008. Disponível em: https://cubo.ufro.cl/ojs/index.php/cubo/article/view/1497. Acesso em: 24 apr. 2024.