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) ·

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

LL-MAP (Language and Location: A Map Accessibility Project) . Anthony Aristar and Helen Aristar-Dry and Yichun Xie (2012) · http://llmap.org

Ethnologue: Languages of the World, 18th Edition . (2015) · edited by Lewis, M. Paul, Gary F. Simons, and Charles D. Fennig · SIL International http://www.ethnologue.com

Sepik languages: checklist and preliminary classification . Laycock, Donald C. (1973) · Pacific Linguistics · edited by Wurm, Stephen A. · Australian National University, Research School of Pacific Studies, Department of Linguistics