http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Regional water-level changes for the Cambrian-Ordovician aquifer in Iowa, 1975 to 1997
1 online resource (iv, 11 pages) : illustrations, maps.
"Prepared in cooperation with the Iowa Department of Natural Resources-Geological Survey Bureau."
Includes bibliographical references (page 11).
Water-resources investigations report ; 99-4134