BASOV, Vladimir V.; CHERMNYKH, Aleksandr S. Two-dimensional homogeneous cubic systems: classification and normal forms — V. Vestnik of Saint Petersburg University. Mathematics. Mechanics. Astronomy, [S. l.], v. 5, n. 4, p. 556–571, 2020. Disponível em: https://math-mech-astr-journal.spbu.ru/article/view/8481. Acesso em: 18 may. 2024.