FeshchenkoS. F., ShkіlN. I., and SоtnіchenkоN. A. “On Asymptotic Representation of Solutions for a System of Linear Partial Differential Equations With Time Lag”. Ukrains’kyi Matematychnyi Zhurnal 23, no. 2 (February 23, 1971): 177-189. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/8500.