Description
Item Description:Title from PDF title screen (viewed on Nov. 5, 2008).
Edition statement from HTML title screen.
Electronic resource.
Physical Description:iv, 41 pages : digital, PDF file.
Format:Mode of access: Internet via the USGS web site. Address as of 11/18/08: http://pubs.usgs.gov/of/2008/1262/pdf/OF08-1262%5f508.pdf ; current access available via PURL.
Bibliography:Includes bibliographical references.