Ahmed, Fuad Idris, Seleshi Demie Alemu, and Getachew Teshome Tilahu. 2022. “A Single Server Markovian Queue With Single Working Vacation, State Dependent Reneging and Retention of Reneged Customers”. Ethiopian Journal of Education and Sciences 17 (1), 51-69. https://ejhs.ju.edu.et/index.php/ejes/article/view/3976.