The M/G/1 FIFO Queue with Several Customer Classes.

Onno J. Boxma Tetsuya Takine The M/G/1 FIFO Queue with Several Customer Classes. 185-189 2003 45 Queueing Syst. 3 http://dx.doi.org/10.1023/A:1027306700614 db/journals/questa/questa45.html#BoxmaT03