SOM, Bhupender Kumar; SETH, Sunny. M/M/c/N QUEUING SYSTEMS WITH ENCOURAGED ARRIVALS, RENEGING, RETENTION AND FEEDBACK CUSTOMERS. Yugoslav Journal of Operations Research, [S.l.], v. 28, n. 3, p. 333–344, mar. 2018. ISSN 2334-6043. Available at: <http://yujor.fon.bg.ac.rs/index.php/yujor/article/view/536>. Date accessed: 16 feb. 2019.