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^ Wotu at Ethnologue (18th ed., 2015) (subscription required)
Donohue, Mark. (2004). "The pretenders to the Muna-Buton group." In Bowden, J. and Himmelmann, N. (eds.). Papers in Austronesian subgrouping and dialectology, pp. 21-36. Canberra: Australian National University. (Pacific Linguistics 563)
Mead, David. (2003). "Evidence for a Celebic supergroup." In Lynch, John (ed.). Issues in Austronesian historical phonology, pp. 115-141. Canberra: Australian National University. (Pacific Linguistics 550)