Turtles of the World: Description of Phrynops williamsi, a new species of chelid turtle of the South American P. geoffroanus complex. In: A. G. J. Rhodin and K. Miyata (eds.), Advances in Herpetology and Evolutionary Biology, pp. 58-73. Mus. Comp. Zool. Harvard. Cambridge, Mass.

Authors(s)	Rhodin, A. G. J., and R. A. Mittermeier.
Year	1983
Title	Description of Phrynops williamsi, a new species of chelid turtle of the South American P. geoffroanus complex. In: A. G. J. Rhodin and K. Miyata (eds.), Advances in Herpetology and Evolutionary Biology, pp. 58-73. Mus. Comp. Zool. Harvard. Cambridge, Mass.