BoichukО. A., S. A. Krivosheya, and A. M. Samoilenko. “Boundary-Value Problems for Systems of Integro-Differential Equations With Degenerate Kernel”. Ukrains’kyi Matematychnyi Zhurnal 48, no. 11 (November 25, 1996): 1576-1579. Accessed May 19, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5213.