http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Summary, ground-water resources of Allegheny County, Pennsylvania
Bureau of Topographic and Geologic Survey.
vii, 71 pages : illustrations, maps (1 folded color in pocket) ; 23 cm.
by John T. Gallaher ; prepared by the United States Geological Survey, Water Resources Division, in cooperation with the Pennsylvania Geological Survey.
"Pennsylvania geological survey fourth series"