^Palmer, Bill (2018). The Languages and Linguistics of the New Guinea Area: A Comprehensive Guide. Berlin: De Gruyter Mouton. p. 665.
^Foley, William A. (2018). "The morphosyntactic typology of Papuan languages". The Languages and Linguistics of the New Guinea Area: A Comprehensive Guide. Vol. 4. The World of Linguistics. Berlin: De Gruyter Mouton. pp. 895–938. ISBN 978-3-11-028642-7.