BratiichukM. S., Chechelnitsky A. A., and UsarI. Ya. “M/M/1 Retrial Queueing Model With Variable Service Rate”. Ukrains’kyi Matematychnyi Zhurnal 72, no. 3 (March 28, 2020): 355-365. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/813.