URMANCHEV, V.I. Methods of the investigation of dynamical systems with pulse effect and “mortal” dynamical systems . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 11, p. 1605–1613, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8264. Acesso em: 7 apr. 2025.