ZavizionG. V. “Asymptotic Integration of Systems of Integro-Differential Equations With Degeneracies”. Ukrains’kyi Matematychnyi Zhurnal 51, no. 2 (February 25, 1999): 170–180. Accessed November 28, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4596.