Telephone transmission quality : series P recommendations / International Telecommunication Union
General recommendations on telephone switching and signalling : functions and information flows for service in the ISDN: supplements: recommendations Q.1- Q.118 bis / International Telecommunication Union
Public land mobile network : interworking with ISDN PSTN: recommendations Q.1000 - Q.1032 / International Telecommunication Union
Public land mobile network : mobile application part and interfaces: recommendations Q.1051 - Q.1063 / International Telecommunication Union