CANDELA, A. M.; DE MEDEIROS, E. S.; PALMIERI, G.; PERERA, K. Weak solutions of quasilinear elliptic eystems via the cohomological index. Topological Methods in Nonlinear Analysis, [S. l.], v. 36, n. 1, p. 1–18, 2010. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2010.024. Acesso em: 25 mar. 2023.