Zavala Maldonado, Robert. 2011. Reciprocal constructions in Olutec.Reciprocals and Semantic Typology, ed. by By Nicholas Evans, Alice Gaby, Stephen C. Levinson, and Asifa Majid, 265-276. Amsterdam: Benjamins.
Campbell, Lyle and Verónica Grondona. 2010. Who speaks what to whom?: Multilingualism and language choice in Misión La Paz – a unique case. Language in Society 39. 1-30.
Anthony Aristar, Helen Aristar-Dry and Yichun Xie. 2012. "LL-MAP (Language and Location: A Map Accessibility Project)." Online: http://llmap.org.
Akinbiyi Akinlabi, Bruce Connell and Ozo-Mekuri Ndimele. 2011. "Defaka & Nkoroo Description & Documentation." Online: http://defaka.rutgers.edu/project.html.