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

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

The Linguistic archeology of the Ryukyu Islands ( pp. 13-37 ) . Pellard, Thomas (2015) · In Handbook of the Ryukyuan languages : history, structure, and use edited by Heinrich, Patrick, Miyara, Shinsho, & Shimoji, Michinori. · De Gruyter Mouton https://doi.org/10.1515/9781614511151

Yonaguni ( pp. 412-457 ch. 14 ) . Izuyama, Atsuko (2012) · In The Languages of Japan and Korea edited by Tranter, Nicolas · Routledge

personal communication on Japonic languages . Thomas Dougherty (2014) ·

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