Anderson, C., E. Epstein, N. Merryfield and W. Smith 2001. The Niagara escarpment: inventory findings 1999-2001 and considerations for management.  Wisconsin Department of Natural Resources, Madison, WI, USA.

Eisenhour, D., C. Hickman, S. Keen, A. Larson, and L. Roberts 2007. Animal diversity-fifth edition. McGraw Hill, Boston, Massachusetts, USA.
Grimm, F.W., R.G. Forsyth, F.W. Schueler, A. Karstad 2009. Identifying land snails and slugs in Canada: introduced species and native genera. Canadian Food Inspection Agency, Canada.
Hotopp, K.P. 2002. Land snails and soil calcium in Central Appalachian Mountain Forest. Southeastern Naturalist. 1:27-44.
Nature Serve 2009. <URL:
> Accessed 14 October 2011.
Nekola, J.C. 2003. Terrestrial gastropod fauna of Northeastern Wisconsin and the Southern Upper Peninsula of Michigan. American Malacological Bulletin 18:21-44.

Nekola, J.C. 2009. Conservation prioritization of the Ontario and Quebec land snail faunas. Pages 1-119. Committee on the Status of Endangered Wildlife In Canada.
Orstan, A. 1999. Land snails of Black Hills Regional Park, Montgomery County, Maryland. The Maryland Naturalist 43:20-24

Wisconsin DNR 2011. <URL:> Accessed 1 October 2011.

Wolfgram Alpha 2011. <URL:> Accessed 14 October 2011.
The world of snails 2008. <URL:> Accessed 29 October 2011.