Bruce Connell. Phonetic Aspects of the Lower Cross Languages and Their Implications For Sound Change. PhD thesis, University of Edinburgh, 1991.

D. Forde. 1956. "Linguistic Survey of the Northern Bantu Borderland." Oxford University Press.

Holly Ann Higgins. Ikoma Vowel Harmony: Phonetics and Phonology. PhD thesis, Trinity Western University, 2011.

Amanda Lissarrague. 2010. "A Grammar and Dictionary of Gathang: The Language of the Birrbay, Guringay and Warrimay." Muurrbay Aboriginal Language and Culture Co-operative.

Barry J. Alpher. 1972. "On the Genetic Subgrouping of the Languages of Southwestern Cape York Peninsula, Australia." In Oceanic Linguistics, 11: 67-68.

Roger Blench. 2009. "The Ejegha Language of Central Nigeria."

Lionel M. Bender. 1985. "Gumuz, Koman, Mao and Omotic." In Papers from the fifteenth conference on African linguistics, edited by Russell G. Schuh. 9: 19-21. University of California.

Marie P. Godfrey. 1970. "Wik-Munkan Verb Morphology." In Pacific Linguistic studies in honour of Arthur Capell, edited by Stephen A. Wurm and D. C. Laycock. 741-756. Australian National University.

Thérèse L. Carr. 2000. "Wunambal: a Language of the North-West Kimberley Region Western Australia." University of New England.

Brett Baker Kate Horrack, Rachel Nordlinger and Louisa Sadler. 2010. "Putting It All Together: Agreement, Incorporation, Coordination and Coordination in Wubuy (Australia)."