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) ·

Atlas of the World’s Languages in Danger . Christopher Moseley (ed.) (2010) · UNESCO Publishing http://www.unesco.org/culture/en/endangeredlanguages/atlas

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

South America ( pp. 103-196 ) . Mily Crevels (2007) · In Atlas of the World's Endangered Languages edited by C. Moseley · London & New York: Routledge

Language endangerment in South America: The clock is ticking ( pp. 167-234 ) . Crevels, Mily (2012) · In The Indigenous Languages of South America: A Comprehensive Guide edited by Lyle Campbell and Veronica Grondona · Mouton de Gruyter

Learning the World's Languages Before They Vanish ( pp. 1156-1159 ) . Bernice Wuethrich (2000) · Science. 288 (5469) · http://www.jstor.org/stable/3075227?origin=JSTOR-pdf

Ethnologue: Languages of the World, 16th Edition (2009) . (2009) · edited by M. Paul Lewis · SIL International http://www.ethnologue.com/

The World Atlas of Language Structures . (2005) · edited by Bernard Comrie and David Gil and Martin Haspelmath and Matthew S. Dryer · Oxford University Press

Classification of the indigenous languages of South America ( pp. 59-166 ) . Campbell, Lyle (2012) · In The Indigenous Languages of South America: A Comprehensive Guide The World of Linguistics · Vol. 2 · edited by Lyle Campbell and Verónica Grondona · Mouton de Gruyter

Étude du Samba Leko, parler d'Allani (Cameroun du Nord, Famille Adamawa) . Anne Gwenaïélle Fabre (2002) ·

The Native Tribes of Eastern Bolivia and Western Matto Grosso . Alfred Métraux (1942) · Bureau of American Ethnology: Bulletin · Vol. 134 · Washington, D.C.: Smithsonian Institution

Études sur les Populations Indigènes de la Bolivie: Populations du Piémont Andin . Jean-Albert Vellard (1973) · Monographies du Centre d'Hémotypologie · Toulouse

El Leko ( pp. 287-332 ) . Simon van de Kerke (2009) · In Ambito Andino Lenguas de Bolivia · Vol. 1 · edited by Pieter Muysken and Mily Crevels · La Paz: Plural Editores

Complex Verb Formation in Leko ( pp. 241-254 ) . S. van de Kerke (2002) · In Current Studies on South American Languages Lenguas Indígenas de América Latina (ILLA) · Vol. 3 · edited by Mily Crevels and Simon van de Kerke and Sérgio Meira and Hein van der Voort · Netherlands: Research School of Asian, African and Amerindian Studies (CNWS), Universiteit Leiden

The American Race: A Linguistic Classification and Ethnographic Description of the Native Tribes of North and South America . Daniel G. Brinton (1891) · New York: N.~D.~C.~Hodges Publisher

Las Misiones Franciscanas entre los Infieles de Bolivia: descripción del estado de ellas en 1883 y 1884 . (1886) · Barcelona: Librería de la inmaculada concepción

Complex verb formation in Leko ( pp. 241-254 ) . van de Kerke, Simon (2002) · In Current Studies on South American Languages Indigenous Languages of Latin America · Vol. 3 · edited by Mily Crevels et al. · Research School of Asian, African and Amerindian Studies, Universiteit Leiden.