O. R. Shlepakov, “Asymptotic Representations for the Solutions of One Class of Nonlinear Differential Equations of the Second Order”, Ukr. Mat. Zhurn., vol. 67, no. 9, pp. 1285–1293, Sep. 2015, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/2065