Kadankov, V. F., and T. V. Kadankova. “Two-Boundary Problems for a Poisson Process With Exponentially Distributed Component”. Ukrains’kyi Matematychnyi Zhurnal 58, no. 7 (July 25, 2006): 922–953. Accessed April 25, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3506.