1. Abdollahi, S., Salehirad, M.R.: On an M/G/1 queueing model with K-Phase optional services and Bernoulli feedback. J. Serv. Sci. Manage. 5, 280–288 (2012)
2. Arivudainambi, D., Gowsalya, M.: Performance analysis of an M/G/1 feedback retrial queue with two types of service and Bernoulli vacation. Stochastic Process. Models Oper. Res. 38–54 (2016)
3. Artalejo, J.R., Atencia, I., Moreno, P.: A discrete time Geo[X]/G/1 retrial queue with control of admission. Appl. Math. Model. 29, 1100–1120 (2005)
4. Bagyam, J.E.A., Udaya Chandrika, K.: Bulk arrival two phase retrial queue with two types service and extended Bernoulli vacation. Int. J. Math. Trends Technol. 4(7), 116–124 (2013)
5. Bagyam, J.E.A., Udaya Chandrika, K.: Multi-stage retrial queueing system with Bernoulli feedback. Int. J. Sci. Eng. Res. 4(9), 496–499 (2013)