V. V. Pham and T. Vu, “On the Asymptotic Behavior of Solutions of Differential Systems”, Ukr. Mat. Zhurn., vol. 57, no. 1, pp. 137–142, Jan. 2005, Accessed: Feb. 16, 2026. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3581