Tài liệu tham khảo WikiPedia: Ethnologue http://www.ethnologue.com/ http://www.ethnologue.com/ethno_docs/introduction.... http://www.nytimes.com/2005/07/19/science/19lang.h... http://xml.coverpages.org/langcodesEth.txt http://www-01.sil.org/~simonsg/preprint/EGIDS.pdf http://www.sil.org/iso639-3/scope.asp
