1. L.G. Afanas'eva, On the ergodicity of open queueing network, Prob. Theory Appl. 32 (1987) 777?781.
2. F. Baccelli and P. Brémaud,Palm Probabilities and Stationary Queues (Springer, 1987).
3. F. Baccelli and P. Brémaud,Elements of Queueing Theory (Springer, 1994).
4. F. Baccelli, G. Cohen and B. Gaujal, Recursive equation and basic properties of timed Petri nets, J. Dynam. Discr. Event Syst. 1 (1992) 415?239.
5. F. Baccelli, G. Cohen, G. Olsder and J.P. Quadrat,Linearity and Synchronization (Wiley, 1992).