SAMOILENKO, A. M. On the Asymptotic Integration of a System of Linear Differential Equations with a Small Parameter in the Coefficients of a Part of Derivatives. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 11, p. 1505–1517, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4188. Acesso em: 5 dec. 2025.