Digital cellular telecommunications system (Phase 2) - Base Station System (BSS) equipment specification - Part 2: Signalling aspects (GSM 11.23 version 4.9.1)
Digital cellular telecommunications system (Phase 2) - Attachment requirements for Global System for Mobile communications (GSM) - Part 1: Mobile stations in the GSM 900 and DCS 1 800 bands - Access (GSM 13.01 version 4.1.1)
