Permian gastropoda of the southwestern United States : 1. Euomphalacea, Trochonematacea, Pseudophoracea, Anomphalacea, Craspedostomatacea, and Platyceratacea /
Ellis L. Yochelson.
-- New York : [s.n.], 1956
- p. 177-275, [8]p. de lám. --
(Bulletin of the American Museum of Natural History ; 110, 3).