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) ·

Endangered Languages in Central Africa ( pp. 163-178 ) . Bruce Connell (2007) · In Language Diversity Endangered edited by Matthias Brenzinger · Mouton de Gruyter

One Thousand Languages: Living, Endangered, and Lost . Peter Austin (2008) · University of California

Africa ( ch. 7 ) . Gerrit J. Dimmendaal and F. K. Erhard Voeltz (2007) · In Encyclopedia of the World's Endangered Languages edited by Christopher Moseley · Routledge

Njerep: A Postcard from the Edge ( pp. 95-125 ) . Bruce A. Connell and David Zeitlyn (2000) · Studies in African Linguistics. 29 (1) · http://oxford.academia.edu/DavidZeitlyn/Papers/1035537/Njerep_A_postcard_from_the_edge

Moribund Languages of the Nigeria-Cameroon Borderland ( pp. 207-225 ) . Bruce Connell (1998) · In Endangered Languages in Africa edited by Matthias Brenzinger · Köppe Verlag