PRECUP, Radu; VARGA, Csaba. Localization of positive critical points in Banach spaces and applications. Topological Methods in Nonlinear Analysis, [S. l.], v. 49, n. 2, p. 817–833, 2017. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2017.011. Acesso em: 5 feb. 2025.