Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) - Enhancements for support of Number Portability (NP) [ITU-T Recommendation Q.769.1 (2000), modified]
Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 1: Basic services [ITU-T Recommendations Q.761 to Q.764 (1999), modified]
Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 2: ISDN supplementary service [ITU-T Recommendation Q.730 (1999), modified]
Digital cellular telecommunications system (Phase 2+) - Support of Mobile Number Portability (MNP) - Technical Realisation - Stage 2 (GSM 03.66 version 7.3.1 Release 1998)
