00257nam a2200109Ia 4500008004100000041000800041082001600049100002100065245002200086260003200108365000700140230303s9999    xx            000 0 und d  aeng  a621.385 BEL  aBELLAMY (JOHN C)  aDigital Telephony  aNEW YORKbJOHN WILEY & SONS  cRS