GĘBA, K.; MARZANTOWICZ, W. Global bifurcation of periodic solutions. Topological Methods in Nonlinear Analysis, [S. l.], v. 1, n. 1, p. 67–93, 1993. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1993.008. Acesso em: 25 apr. 2024.