HOLUBOVÁ, G.; NEČESAL, P. Fučík spectrum in general: principal eigenvalues and inadmissible sets. Topological Methods in Nonlinear Analysis, [S. l.], v. 44, n. 1, p. 11–21, 2016. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2014.033. Acesso em: 29 mar. 2024.