Bratiychuk, A. M. “Rate of Convergence to Ergodic Distribution for Queue Length in Systems of the $M^{θ} G 1 N$”. Ukrains’kyi Matematychnyi Zhurnal 59, no. 9 (September 25, 2007): 1169–1178. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/3380.