European digital cellular telecommunications system (Phase 2) - Mobile Station - Base Station System (MS-BSS) interface - Data Link (DL) layer specification; English version ETS 300555:1994
Edition 1995-01

Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol; signalling network layer for circuit-mode basic call control - Part 5: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the user; English version ETS 300403-5:1997
Edition 1998-08

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

Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol - Signalling network layer for circuit-mode basic call control - Part 4: Test Suite Structure and Test Purposes (TSS&TP) specification for the user; English version ETS 300403-4:1997
Edition 1997-11

Integrated Services Digital Network (ISDN); user-network interface layer 3; specification for basic call control; english version ETS 300102-1:1990
Edition 1992-02