MARÒ, S. Periodic solutions of a forced relativistic pendulum via twist dynamics. Topological Methods in Nonlinear Analysis, [S. l.], v. 42, n. 1, p. 51–75, 2013. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2013.024. Acesso em: 22 lip. 2024.