SKIBA, R. Applications of weighted maps to periodic problems of autonomous differential equations. Topological Methods in Nonlinear Analysis, [S. l.], v. 42, n. 1, p. 9–49, 2013. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2013.023. Acesso em: 22 jul. 2024.