1. Michael , C.H. 2008 http://www.dnr.state.oh.Us/tabid/7906/default.aspx 2013
2. EPA'S strategy to reduce risk of radon;Page;Journal of Environment and Health,1993
3. U.S. Environmental Protection Agency. Information on Radon http://www.epa.gov/radon/index.html 2013
4. Radon hazards associated with outcrops of Ohio Shale in Ohio;Harrell;Environmental Geology and Water Sciences,1991
5. Ohio goes online to combat indoor Radon;Kumar;EM (by A&WMA),2001