Integrated Services Digital Network (ISDN) - User-to-User Signalling (UUS) supplementary service - Service description; English version ETS 300284:1996
Telecommunications Management Network (TMN) - Functional specification of Customer Administration (CA) on the Operations System/Network Element (OS/NE) interface - Part 1: Single line configurations
Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 8: User-to-User Signalling (UUS) supplementary service [ITU-T Recommendation Q.737, clause 1 (1997), modified]