The specification of abbreviations for GSM can be found in

ftp://ftp.3gpp.org/specs/2002-03/R1999/01_series/

The name of the file is '0104-800.zip'.

 

The way to download the specification of abbreviations for UMTS is a little bit tricky. This specification in 3GPP is '3G TR 25.990 version 3.0.0 release 1999', which hasn't been put on their website. You could download it from ETSI,

http://webapp.etsi.org/key/queryform.asp

by putting '25.990' into the search dialog box. However, you need first do some registration then can you download it. If any problem, please contact the assistant.