IP voice services : European corporate market forecasts, 2002-2007 / Margaret Hopkins
IP Interconnect : commercial, technical and regulatory dynamics / David Rogerson...[et. al.]
Ovum forecasts : global IP and broadband markets / Richard Kee ... [et. al.]
Annual review of communications / IEC - International Engineering Consortium
Wireless internet access over GSM and UMTS / Manfred Taferner, Ernst Bonek
SIP demystified / Gonzalo Camarillo