Integrated Services Digital Network (ISDN); user-network interface data link layer specification; application of CCITT recommendations Q.920/I.440 and Q.921/I.441; english version ETS 300125:1991
Edition 1992-05

Private Integrated Services Network (PISN) - Inter-exchange signalling protocol, Circuit mode basic services, Data Link Layer (DLL) - Part 2: Abstract Test Suite (ATS) specification; English version ETS 300804-2:1998
Edition 1998-12

Radio Equipment and Systems (RES) - Terrestrial Flight Telephone System (TFTS) - Packet mode data; English version ETS 300752:1997
Edition 1998-07

Industrial communication networks - Fieldbus specifications - Part 6-7: Application layer protocol specification - Type 7 elements (IEC 61158-6-7:2007); English version EN 61158-6-7:2008, only on CD-ROM
Edition 2008-09