EVTUKHOV, V. M. On Some Problems of the Asymptotic Theory of Linear Differential Equations of the nth Order. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 1, p. 20–42, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4037. Acesso em: 11 apr. 2025.