Integrated Services Digital Network (ISDN); 3,1 kHz telephony teleservice; end-to-end compatibility requirements for telephony terminals; english version ETS 300082:1992
Integrated Services Digital Network (ISDN) - Telephony 7 kHz, videotelephony, audiographic conference and videoconference teleservices - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 1: Protocol specification
