Title from title screen (viewed on Dec. 15, 2003).
Includes bibliographical references.
System requirements: Adobe Acrobat Reader.
Mode of access: Internet at the USGS web site. Address as of 12/15/03: http://water.usgs.gov/pubs/wri/wri014278/pdf/WRIR01%5F4278.pdf; current access available via PURL.