References
1. Orstan, A. 1999. Land Snails of Black Hill Regional Park, Montgomery County, Maryland. The Maryland Naturalist. 43(3-4):20-24
2. Barger, M., and Hnida, J. 2008. Survey of Trematodes from Terrestrial Gastropods and Small Mammals in Southeastern Nebraska, U.S.A. Comparative Parasitology. 75(2):308-314. 2008
3.Sturm, C.F., Pearce, T.A., and Valdes, A. 2006. The Mollusks: A Guide to their Study, Collection, and Preservation. Ch 22-23.
7. Pilsbry, H.A. 1939-1948. Land Mollusca of North America (north of Mexico). Monographs of the Academy of Natural Sciences of Philadelphia, 2 (parts 1-4)
8. Dourson, D., and Dourson, J. 2006. Land Snails of the Great Smoky Mountains.
9. McCraken, G. F., and Brussard, P.F. 2008. Self-fertilization in the white-lipped land snail Triodopsis Albolabris. Biological Journal of the Linnean Society. 41(3-4):429-434
10. Ingram, W. 1941. American Midland Naturalist. pp 644-651.
11. Nordsieck, R. 2011. The Living World of Molluscs. http://www.weichtiere.at/english/gastropoda/terrestrial/main.html