M. F. Gorodnii, “Stability of Bounded Solutions of Differential Equations with Small Parameter in a Banach Space”, Ukr. Mat. Zhurn., vol. 55, no. 7, pp. 889–900, Jul. 2003, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3964