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

Explorations in South Africa, with Route from Walfisch Bay to Lake Ngami, and Ascent of the Tiogé River ( pp. 79-107 ) . Charles J. Andersson (1855) · Journal of the Royal Geographical Society of London. 25

On the Central South African Tribes from the South Coast to the Zambesi ( pp. 2-20 ) . Emil Holub (1881) · Journal of the Royal Anthropological Institute of Great Britain and Ireland. 10