Endangered Languages Catalogue Project. Compiled by research teams at University of Hawai'i Mānoa and Institute for Language Information and Technology (LINGUIST List) at Eastern Michigan University . (2012) ·

Ethnologue: Languages of the World, 16th Edition (2009) . (2009) · edited by M. Paul Lewis · SIL International http://www.ethnologue.com/

Atlas of the World’s Languages in Danger . Christopher Moseley (ed.) (2010) · UNESCO Publishing http://www.unesco.org/culture/en/endangeredlanguages/atlas

World Oral Literature Project . http://www.oralliterature.org

1994 Population and Housing Census of Ethiopia, Results at Country Level . (1998) · Central Statistical Office https://www.msu.edu/~hudson/Ethlgslist.htm

Sociolinguistic survey report of the languages of the Gawwada, Tsamay and Diraasha areas with excursions to Birayle (Ongota) and Arbore (Irbore) part II . Wedekind, Klaus (2002) · SIL Electronic Survey Reports. 2002-066 http://www.sil.org/silesr/abstract.asp?ref=2002-066

Ts'amakko morphological borrowings in Ongota (or Birale) ( pp. 75-93 ) . (2002) · In Proceedings of the 1st International Symposium 'Ethiopian Morphosyntax in an Areal Perspective' Afrikanistische Arbeitspapiere · Vol. 71 · Universität zu Köln