References
Dourson, Daniel. 2010. Kentucky's Land Snails and Their Ecological Communities. Goatslug Publications, Bakersville.
Emberton, Kenneth. 1998. “Proceedings of the Academy of Natural Sciences of Philadelphia: Shell Variation in a Population of Polygyra septemvolva (Pulmonata: Polygyridae).” Vol. 140, No. 1, pp. 285-294. Academy of Natural Sciences, <http://www.jstor.org/stable/4064929>.
Hickman, C., Roberts, L., Keen, S., Larson, A., and Eisenhour, D. 2009. Animal Diversity. McGraw-Hill, New York.
Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. 2012. The Animal Diversity Web. Accessed at http://animaldiversity.org.
Perez, K. E. and Cordeiro, J. R. 2008. A Guide for Terrestrial Gastropod Identification. American Malacological Society. 51. http://www.uwlax.edu/biology/faculty/perez/Perez/PerezLab/Research/Publications/AMS_Workbook_KEP_FINAL.pdf
Pilsbry, Henry. 1940. Land of Mollusca of North America: North of Mexico. Wickersham Printing Company, Lancaster.
Wilbur, Karl, ed. 1985. The Mollusca. Academic Press, INC, Orlando.
Wilbur, Karl and Yonge, C.M. eds. 1996. Physiology of Mullosca. Vol. 2. Academic Press Inc., New York.
Weber, Karl, ed. 1984. The Mollusca: Reproduction. Academic Press, INC, Orlando.