1. Water levels in, extent of freshwater in, and water withdrawals from ten confined aquifers, New Jersey and Delaware coastal plain, 1998 Author/Creator: Geological Survey (U.S.) Publication/Creation: [West Trenton, N.J.] : The Survey, 2001 Resource Type: Map Access & Availability: Loading
2. Atlas of historical county boundaries. Delaware, Maryland, and the District of Columbia Publication/Creation: New York : Charles Scribner's Sons, Simon & Schuster Macmillan, 1996 Resource Type: Map Access & Availability: Loading
3. Delaware, District of Columbia, and Maryland Author/Creator: United States. Bureau of the Census. Geography Division Publication/Creation: Washington, D.C. : U.S. Dept. of Commerce, Bureau of the Census, [1983] Resource Type: Map Access & Availability: Loading