ETSI PRETS 300 938-1997 Digital Cellular Telecommunications System (Phase 2+); Mobile Station - Base Station System (MS - BSS) Interface; Data Link (DL) Layer Specification GSM 04.06 Version 5.1.0; Second Edition
1999ETSI PRETS 300 938-1999 Digital Cellular Telecommunications System (Phase 2+); Mobile Station - Base Station System (MS - BSS) Interface; Data Link (DL) Layer Specification Fourth Edition; GSM 04.06 Version 5.3.0 Release 1996
1998ETSI PRETS 300 938-1998 Digital Cellular Telecommunications System (Phase 2+); Mobile Station - Base Station System (MS - BSS) Interface; Data Link (DL) Layer Specification Third Edition; GSM 04.06 Version 5.2.0
1997ETSI PRETS 300 938-1997 Digital Cellular Telecommunications System (Phase 2+); Mobile Station - Base Station System (MS - BSS) Interface; Data Link (DL) Layer Specification GSM 04.06 Version 5.1.0; Second Edition
1996ETSI PRETS 300 938-1996 Digital Cellular Telecommunications System; Mobile Station - Base Station System (MS - BSS) Interface Data Link (DL) Layer Specification (GSM 04.06 Version 5.0.0)