LUCIA, M. A deformation lemma with an application to a mean field equation. Topological Methods in Nonlinear Analysis, [S. l.], v. 30, n. 1, p. 113–138, 2007. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2007.021. Acesso em: 22 jul. 2024.