V. M. Evtukhov and V. A. Kas'yanova, “Asymptotic Behavior of Unbounded Solutions of Essentially Nonlinear Second-Order Differential Equations. I”, Ukr. Mat. Zhurn., vol. 57, no. 3, pp. 338–355, Mar. 2005, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3602