SlyusarchukV. Yu. “A Criterion for the Existence of Almost Periodic Solutions of Nonlinear Differential Equations With Impulsive Perturbation”. Ukrains’kyi Matematychnyi Zhurnal 67, no. 6 (June 25, 2015): 838–848. Accessed November 21, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2026.