PILUGIN, Sergey Yu.; RODIONOVA, Anastasiya A. Systems that generate solutions with small period. Vestnik of Saint Petersburg University. Mathematics. Mechanics. Astronomy, [S. l.], v. 3, n. 3, p. 424–428, 2020. Disponível em: https://math-mech-astr-journal.spbu.ru/article/view/8688. Acesso em: 18 may. 2024.