Mode of access: Internet from the USGS Web site. Address as of 6/16/04: http://pubs.usgs.gov/bul/b2182/b2182.pdf; current access is available via PURL.
Note
Title from PDF title screen (viewed June 16, 2004).
"Posted online January 2001, version 1.0; April 2001, version 1.1."