Conselho de Ministros de telecomunicações [documento electrónico] : 27 de Abril 1989 / Instituto das Comunicações de Portugal
Telephone network and ISDN : quality of service, network management and traffic engineering: recommendations E.401 - E.880 / International Telecommunication Union
Integrated services digital network (ISDN) : general structure and service capabilities: recommendations I.110 - I.257 / International Telecommunication Union
General recommendations on telephone switching and signalling : functions and information flows for service in the ISDN: supplements: recommendations Q.1- Q.118 bis / International Telecommunication Union
Integrated services digital network (ISDN) : 3.1 kHz telephony teleservice: attachment requirements for handset terminals: NET 33 / European Conference of Postal and Telecommunications Administrations
Approval requirements for terminal equipment to connect to packet integrated services digital network (ISDN) using ISDN basic access : NET 3 / European Conference of Postal and Telecommunications Administrations
Telephone network and ISDN : operation, numbering, routing and mobile service: recommendations E.100 - E.333 / International Telecommunication Union
Integrated services digital network (ISDN) : internetwork interfaces and maintenance principles: recommendations I.500 - I.605 / International Telecommunication Union
Integrated services digital network (ISDN) : overall network aspects and functions, ISDN user-network interfaces: recommendations I.310 - I.470 / International Telecommunication Union