Fisher, W. L., Rodda, P. U., and Dietrich, J. W., 1964, Evolution of Athleta
petrosa stock (Eocene, Gastropoda) of Texas, Publication 6413 of
University of Texas Bureau of Economic Geology: p.1-117.
Sohl, N. F., 1960, Archeogastropoda, Mesogastropoda, and stratigraphy of the
Ripley, Owl Creek, and Prairie Bluff Formations: United States Geological
Survey, Professional Paper, v. 331-A, p. 1-151.
---, 1967, Upper Cretaceous gastropods from the Pierre Shale at Red Bird,
Wyoming: United States Geological Survey, Professional Paper, v. 393-B, p.
B1-B46.