Portenko, N. I. “On Renewal Equations Appearing in Some Problems in the Theory of Generalized Diffusion Processes”. Ukrains’kyi Matematychnyi Zhurnal 57, no. 9 (September 25, 2005): 1302–1312. Accessed May 9, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3686.