References

Badra, P.J. 2008. Special Animal Abstract for Planogyra asteriscus (eastern flat- whorl). Michigan Natural Features Inventory. Lansing, MI. 4pp.

Baker, F. C. "Land and freshwater mollusca from North Star Lake and vicinity, Itasca County, Minnesota." The American midland naturalist 16.3 (1935):257.

Encyclopedia of Life. Available from http://www.eol.org. Accessed 15 Jan 2009

Martin, S M. (2000). Terrestrial snails and slugs (mollusca: Gastropoda) of maine. Northeastern naturalist, 7    (1), 33.

Nordsieck, R. (1999-2010): "The living world of molluscs", http://www.weichtiere.at/english

Tryon, G.W. (1866). American Journal of Conchology,2, 263 & 276.

Winslow, M.L. (1926). Occasional papers of the museum of zoology a revised checklist of michigan mollusca. University of Michigan Press, (181), 1-28

http://www.weichtiere.at/english/gastropoda/morphology/reproduction.html

http://www.bioone.org/doi/full/10.1656/1092-6194%282000%29007%5B0033%3ATSASMG%5D2.0.CO%3B2

http://www.uwlax.edu/biology/faculty/perez/Perez/PerezLab/Research/WIsnailslist.htm

Http://multipleorganisms.net