Alem, Lala Maghnia, Mohamed Boualem, and Djamil Aissani. 2019. “Bounds of the Stationary Distribution in M G 1 Retrial Queue With Two-Way Communication and N Types of Outgoing Calls”. Yugoslav Journal of Operations Research 29 (3):375-91. https://doi.org/10.2298/YJOR180715012A.