. S. P. . Rogovchenko, “Application of asymptotic method to the study of one hyperbolic impulse system”, Ukr. Mat. Zhurn., vol. 40, no. 2, pp. 244–248, Feb. 1988, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/9126