http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Ground-water levels in the lower Paleozoic and Precambrian crystalline rocks, of East Bradford and West Bradford townships, Chester County, Pennsylvania, July and August 1987
Chester County Water Resources Authority
Relief shown by contours and spot heights.
"Prepared in cooperation with the Chester County Water Resources Authority."
Water-resources investigations report ; 88-4052