Also available online in PDF format from the U.S. Geological Survey Warehouse (http://pubs.er.usgs.gov/).
Bibliography
Includes bibliographical references.
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
Processing Action
digitized 2015 University of North Texas committed to preserve pda TXdn.010