KOSHLYAKOV, V. N. On structural transformations of equations of perturbed motion for a certain class of dynamical systems. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 4, p. 535–539, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5028. Acesso em: 17 apr. 2025.