Derbyshire, Desmond C. and Doris L. Payne. 1990. "Noun Classification Systems of Amazonian Languages." In Amazonian Linguistics, Studies in Lowland South American Languages, edited by Doris L. Payne. 243-271. University of Texas Press.
Barnes, Janet. 1990. "Classifiers in Tuyuca." In Amazonian Linguistics, Studies in Lowland South American Languages, edited by Doris L. Payne. 273-292. University of Texas Press.
Aikhenvald, Alexandra Y. 1999. "Areal Diffusion and Language Contact in the Içana-Vaupés Basin, North-West Amazonia." In The Amazonian Languages, edited by R. M. W. Dixon and A. Y. Aikhenvald. 384-416. Cambridge University Press.
