TANG, S.; ZHANG, X. Subharmonic solutions and minimal periodic solutions of first-order variant subquadratic Hamiltonian systems. Topological Methods in Nonlinear Analysis, [S. l.], v. 55, n. 2, p. 517–532, 2020. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2019.105. Acesso em: 22 jul. 2024.