ETSI TS 124391 V 16.0.0,3GPP TS 24.391 Version 16.
Universal Mobile Telecommunications System (UMTS) – LTE – Unstructured Supplementary Service Data (USSD) unter Verwendung von IP Multimedia (IM) Core Network (CN) Subsystem (IMS) Management Object (MO) (3GPP TS 24.391 Version 16.0.0 Release 16)