http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
7 unnumbered pages, 541 pages : digital, PDF file.
Title from title screen (viewed March 12, 2008).
"This volume includes all revisions of the keys that have so far been approved"--Foreword.
Mode of access: Internet from the USDA web site. Address as of 3/12/2008: ftp://ftp-fc.sc.egov.usda.gov/NSSC/Soil%5FTaxonomy/keys/1992%5FKeys%5Fto%5FSoil%5FTaxonomy.pdf ; current access available via PURL.
Includes bibliographical references and index.