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
Specifications of signalling system No. 7 : recommendations Q.930 - Q.940 / International Telecommunication Union
Public land mobile network : mobile application part and interfaces: recommendations Q.1051 - Q.1063 / International Telecommunication Union
Interworking with satellite mobile systems : recommendations Q.1100 - Q.1152 / International Telecommunication Union