Roger Blench. 2011. "The Ayu Language of Central Nigeria and Its Affinities." Online: http://www.rogerblench.info/Language/Niger-Congo/BC/Plateau/Ninzic/Ayu%….
Roger Blench. 2007. "The Ayere and Ahan Languages of Central Nigeria and Their Affinities." Online: http://www.rogerblench.info/Language/Niger-Congo/VN/Ayere/Ayere%%20word….
Bleek, W. H. I. 1869. "The Bushman Language." In The Cape and its people, and other essays, edited by Roderick Noble. 268-284. Cape Town: J. C. Juta.