http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Exploratory drilling for evidence of zinc and lead ore in Dubuque County, Iowa
1 online resource (iii, 471-499 pages) : illustrations, map, charts.
Title from title screen (viewed July 22, 2014).
"Prepared in cooperation with the Iowa Geological Survey."