References

Dillon, R.T., Jr., B.T. Watson, and T.W. Stewart. 2006. The freshwater gastropods of North America.<URL:http://spinner.cofc.edu/~fwgna/species/planorbidae/h_trivolvis.html?referrer=webcluster&>.
Accsessed 3 November 2011.

EOL 2011. <URL: http://eol.org/pages/10711709/overview>. Accessed 3 November 2011.

Hickman, C., L. Roberts, S. Keen, A. Larson, D. Eisenhour. 2009. Animal Diversity. 5th ed. McGraw-Hill Companies. 186-191.

Keep, J. 1904. West American Shells. The Whitaker and Ray Company.

Klockars, J., J. Huffman, and B. Fried. 2007. Survey of seasonal Trematode infections in Helisoma trivolvis(Gastropoda) from Lentic Ecosystems in New Jersey, USA. Comparative Parasitology 74:75-80.

Norton, C., A. Johnson, and R. Mueller. 2004. Relative Size Influences Gender Role in the Freshwater Hermaphroditic snail, Helisoma trivolvis. Biology Department, College of St Catherine, Randolph Avenue, St Paul, MN, USA.

Smith, D., and D. Russell-Hunter. 1989. Correlation of Abnormal Radular Secretion with Tissue Degrowth During During Stress Periods in Helisoma Trivolvis. The Biological Bulletin. 178: 25.