VOSKRESENSKII, E. V. Groups the lyapunov transformations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 12, p. 1595–1600, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5966. Acesso em: 11 apr. 2025.