"Prepared in cooperation with the Wisconsin Geological and Natural History Survey, the Illinois State Geological Survey, and the Iowa Geological Survey.
Bibliography
Includes bibliographical references (pages 242-243) and index.
System Details
Master and use copy. Digital master created according to Technical Guidelines for Digitizing Archival Materials for Electronic Access. U.S. National Archives and Records Administration, 2004. http://www.archives.gov/preservation/technical/guidelines.html TxDN