http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Ground-water levels in the Lower Paleozoic carbonate rocks of western Chester Valley, Chester County, Pennsylvania, November 1984
Chester County Water Resources Authority
by Charles R. Wood ; prepared in cooperation with the Chester County Water Resources Authority.
Relief shown by contours and spot heights.
Water-resources investigations report ; 85-4224