References
- Abate , J. and Whitt , W. 1988 . Queueing Theory and its applications , Amsterdam : North-Holland . Liber Amicorum for J.W. Cohen
- Saaty , T.L. 1961 . Eleements of Queueing Theory with Applications , New York : McGraw Hill .
- Sharma , O.P. 1990 . Markovian Queues , England : Ellis Horwood .