ITU-T E.169-2002
全球使用国家代码国际电信服务全球国际电话号码E. 164编号方案应用推荐 E系列:全面网络运行,电话
Application of Recommendation E.164 numbering plan for universal international numbers for international telecommunications services using country codes for global services SERIES E: OVERALL NETWORK OPERATION TELEPHONE SERVICE SERVICE OPERATION AND HUMAN