1. American Public Health Association (APHA), 1996. Standard Methods for the Examination of Water and Wastewater, 19th ed. (Suppl. 21–23), American Public Health Association, Washington, DC.
2. Mechanisms of radon release in rock matrices and entry into groundwaters;Andrews;Inst. Mining Metallurgy,1972
3. Bloomer, R.D., 1938. Geology of the Piedmont in Chesterfield and Henrico Counties of Virginia. M.S. Thesis, Department of Geology, University of Virginia.
4. Variation of 222Rn in public drinking water supplies;Drane;Health Phys.,1997
5. Engineers guide to the elementary behavior of radon daughters;Evans;Health Phys.,1969