1. Factors affecting groundwater quality in the Valley and Ridge aquifers, eastern United States, 1993-2002 Publication/Creation: Reston, Va. : U.S. Dept. of the Interior, U.S. Geological Survey, 2011 Resource Type: Book Access & Availability: Loading
2. Factors affecting water quality in selected carbonate aquifers in the United States,1993-2005 Publication/Creation: Reston, Va. : U.S. Geological Survey, 2009 Resource Type: Book Access & Availability: Loading