000 00208 a2200097 4500
001 57460
100 _a
245 _aPBX systems for IP telephony
260 _aNY
_bMcGraw -Hill
_c2002
090 _c35192
_d35192
942 _aNUST-CAE
_c
_c27994
999 _c292533
_d292533