Terms and definitions abbreviations and acronyms : recommendations on means of expression (series B): general telecommunications statistics (series C) / International Telecommunication Union
Index of blue book / International Telecommunication Union
Telephone network and ISDN : operation, numbering, routing and mobile service: recommendations E.100 - E.333 / International Telecommunication Union
Telegraph and mobile services operations and quality of service : recommendations F.1 - F.140 / International Telecommunication Union