USGS reference materials program [electronic resource] : serving the needs of the global analytical community / [written by Ruth E. Wolf and Stephen A. Wilson].
Mode of access: Internet from the USGS web site. Address as of 9/21/07: http://pubs.usgs.gov/fs/2007/3056/pdf/fs07-3056_508.pdf; current access via PURL.
Note
Title from PDF title screen (viewed on Sept. 4, 2007).