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/

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

An Atlas of Nigerian Languages . Roger Blench (2011) · Mallam Dendo http://www.rogerblench.info/Language/Africa/Nigeria/Atlas%%20of%%20Nigerian%%20Languages-%%20ed%%20III.pdf

The Bole-Tangale languages of the Bauchi Area (northern Nigeria) ( pp. xi, 159 ) . Schuh, Russell Galen (1978) · Marburger Studien zur Afrika- und Asienkunde, Reihe A: Afrika, #13 · Verlag von Dietrich Reimer

Daa, Nii, Sum/Khung: Comparative Vocabulary of the West-Central Himalayan Languages Rawati (Raji) and Khamci (Raute) ( pp. 105-115 ) . Rastogi, Kavita and Jana Fortier (2005) · Indian Linguistics. 66