Bilenko, V. I., K. V. Bozhonok, and S. Yu. Dzyadyk. “Piecewise-Polynomial approximations for the Solutions of Impulsive Differential Equations”. Ukrains’kyi Matematychnyi Zhurnal 71, no. 2 (February 25, 2019): 168-179. Accessed April 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/1429.