DvornykA. V., and TkachenkoV. I. “Almost Periodic Solutions of Systems With Delay and nonfixed times of Impulsive Action”. Ukrains’kyi Matematychnyi Zhurnal 68, no. 11 (November 25, 2016): 1450-1466. Accessed November 21, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/1933.