Mynbayeva, S. T., A. N. Stanzhitskii, and N. A. Marchuk. 2020. “Averaging in Boundary-Value Problems for Systems of Differential and Integrodifferential Equations”. Ukrains’kyi Matematychnyi Zhurnal 72 (2), 245-66. https://umj.imath.kiev.ua/index.php/umj/article/view/1071.