EVTUKHOV, V. M. Asymptotics of Solutions of Nonautonomous Second-Order Ordinary Differential Equations Asymptotically Close to Linear Equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 64, n. 10, p. 1346–1364, 2012. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2663. Acesso em: 5 dec. 2025.