Adam Wierman Takayuki Osogami Mor Harchol-Balter Alan Scheller-Wolf How many servers are best in a dual-priority M/PH/k system? 1253-1272 2006 63 Perform. Eval. 12 http://dx.doi.org/10.1016/j.peva.2005.12.004 db/journals/pe/pe63.html#WiermanOHS06