Usar, I. Y., Makushenko, I. A., & Protopop, I. O. (2020). The convergense rate of stationary distribution of retrial queueing system with queue. Bulletin of Taras Shevchenko National University of Kyiv. Physics and Mathematics, 3, 52-55. https://doi.org/10.17721/1812-5409.2019/3.7