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) ·

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

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

"Documenting traditional agricultural songs and stories of the Sumi Nagas" HRELP Abstract . Amos Teo (2011) · http://www.hrelp.org/grants/projects/index.php?projid=263

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

Personal Communication . Gregory Anderson (2012) ·

A Sema Grammar . M. V. Sreedhar (1980) · Central Institute of Indian Languages: Grammar Series · Vol. 7 · Mysore: Central Institute of Indian Languages