ALI, N. A.; YANCHUK, S. V. Rotary motions of autonomous systems with pulse influence. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 4, p. 591–596, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5036. Acesso em: 14 apr. 2025.