SOSNITSKII, S. P. On the function of hamiltonian action for nonholonomic systems and its application to the investigation of stability. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 51, n. 10, p. 1411–1416, 1999. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4740. Acesso em: 5 dec. 2025.