Description
Item Description:Title from title screen (viewed June 1,2015).
Also available online in PDF format from the U.S. Geological Survey Warehouse (http:/pubs.er.usgs.gov/).
Issued also as House doc. numbers 38, 68th Cong., 1st sess.
Physical Description:1 online resource (iv, 72 pages) : illustrations.
Bibliography:Includes index.