Niranjan S. P. และผู้แต่งคนอื่นๆ. (2019) Optimum cost analysis of batch service retrial queuing system with server failure, threshold and multiple vacations. <i>Songklanakarin Journal of Science and Technology</i>, <i>41</i>(2), 363-374.Niranjan S. P. และผู้แต่งคนอื่นๆ. "Optimum cost analysis of batch service retrial queuing system with server failure, threshold and multiple vacations". Songklanakarin Journal of Science and Technology 41 (2019):363-374.Niranjan S. P. และผู้แต่งคนอื่นๆ. Optimum cost analysis of batch service retrial queuing system with server failure, threshold and multiple vacations. Research and Development Office, Prince of Songkla University:ม.ป.ท. 2019.