ISO 639 - Code for the representation of names of languages. etext.lib.virginia.edu/tei/iso639.html
ISO 639 - Codes for the Representation of the Names of Languages. A useful list. ftp.ics.uci.edu/pub/ietf/http/related/iso639.txt
ISO 639 Languages and Dialects - Code for the representation of names of languages, with additional informative data and references. www.laurentia.com/iso639/lang-en.htm