AKHMETOV, M. U. On the expansion of solutions to differential equations with discontinuous right-hand side in a series in initial data and parameters. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 5, p. 715–717, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5858. Acesso em: 14 apr. 2025.