Digital networks, digital sections and digital line systems : recommendations G.801 - G.961 / International Telecommunication Union
Line transmission of non-telephone signals : transmission of sound-programme and television signals: series H and J recommendations / 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
Integrated services digital network (ISDN) : internetwork interfaces and maintenance principles: recommendations I.500 - I.605 / International Telecommunication Union