http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Also available via Internet from the NRC web site. Address as of 5/14/03: http://www.nrc.gov/reading-rm/doc-collections/nuregs/brochures/br0292/br0292.pdf; current access is available via PURL.