地名情報システム
U.S. Department of the Interior, U.S. Geological Survey, National Mapping Division, Digital Gazeteer: Users Manual, (Reston, Virginia: U.S. Geological Survey, 1994).
Least Heat Moon, William, Blue Highways: A Journey Into America, (Boston: Little Brown and Company, 1982). ISBN 0-316-35329-9
Jouris, David, All Over The Map, (Berkeley, California: Ten Speed Press, 1994.) ISBN 0-89815-649-1