S. Pavai Madheswari and S.A. Josephine 2019. Analysis of an \(M / G / 1\) retrial queue with second optional service and customer feedback, under Bernoulli vacation schedule. Malaya Journal of Matematik. 7, 04 (Oct. 2019), 795–807. DOI:https://doi.org/10.26637/MJM0704/0027.