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) ·

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