HA, C.-W.; KUO, C.-C. On the solvability of a two point boundary value problem at resonance. Topological Methods in Nonlinear Analysis, [S. l.], v. 1, n. 2, p. 295–302, 1993. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1993.021. Acesso em: 3 jul. 2024.