http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Preliminary digital model of ground-water flow in the Madison Group, Powder River Basin and adjacent areas, Wyoming, Montana, South Dakota, North Dakota, and Nebraska
1 online resource (v, 44 pages) : illustrations, maps + six plates.
"Prepared in cooperation with Old West Regional Commission."
Includes bibliographical references (pages 43-44).