HEIDARKHANI, S.; HENDERSON, J. Critical point approaches to quasilinear second order differential equations depending on a parameter. Topological Methods in Nonlinear Analysis, [S. l.], v. 44, n. 1, p. 177–197, 2016. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2014.042. Acesso em: 26 apr. 2024.