CASTRO, A.; COSTA, D. G.; SHIVAJI, R. Multiple positive solutions for a class of variational systems. Topological Methods in Nonlinear Analysis, [S. l.], v. 50, n. 1, p. 1–8, 2017. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2017.016. Acesso em: 3 jul. 2024.