GusakD. V. “Sojourn Time of Almost Semicontinuous Integral-Valued Processes in a Fixed State”. Ukrains’kyi Matematychnyi Zhurnal 63, no. 8 (August 25, 2011): 1021-1029. Accessed November 22, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2782.