LI, Shujie; SU, Jiabao. Existence of multiple solutions of a two-point boundary value problem at resonance. Topological Methods in Nonlinear Analysis, [S. l.], v. 10, n. 1, p. 123–135, 1997. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1997.025. Acesso em: 8 jul. 2025.