On periodic motion and bifurcations of three-dimensional nonlinear systems. Neliniini Kolyvannya, [S. l.], v. 17, n. 2, p. 268–280, 2014. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/743. Acesso em: 21 jan. 2026.