PERESTYUK, N. A. On invariance of some properties of solutions under perturbation of a pulse system of differential equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 46, n. 12, p. 1707–1713, 1994. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5579. Acesso em: 5 dec. 2025.