SVISTUN, O. P. On separatrix curves of a family of linear systems with pulse influence. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 12, p. 1682–1687, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5976. Acesso em: 5 dec. 2025.