DRÁBEK, Pavel; LANGEROVÁ, Martina. On the second order equations with nonlinear impulses - Fredholm alternative type results. Topological Methods in Nonlinear Analysis, [S. l.], v. 44, n. 1, p. 249–261, 2016. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2014.046. Acesso em: 8 jul. 2025.