SAMOILENKO, A. M. On the reducibility of a system of ordinary differential equations in the vicinity of a smooth integral manifold . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 18, n. 6, p. 41–64, 1966. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8458. Acesso em: 6 dec. 2025.