Some Karkar-Yuri orthography and spelling decisions ( pp. 57-76 ) . Price, Dorothy (1987) · In Studies in Melanesian orthographies Data Papers on Papua New Guinea Languages · edited by Clifton, John M. · Summer Institute of Linguistics http://www.sil.org/pacific/png/abstract.asp?id=22197

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

Glottolog 2.3 . Hammarström, Harald & Forkel, Robert & Haspelmath, Martin & Nordhoff, Sebastian (2014) · http://glottolog.org