Minkevičius, Saulius, and Stasys Steišūnas. “Laws of Little in an Open Queueing Network”. Nonlinear Analysis: Modelling and Control 17, no. 3 (July 25, 2012): 327–342. Accessed April 30, 2024. https://www.journals.vu.lt/nonlinear-analysis/article/view/14059.