SAMOILENKO, V. G. Integrability of nonlinear dynamical systems and differential geometry structures. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 3, p. 419–427, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5824. Acesso em: 14 apr. 2025.