http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
pt. 1 General principles, fastenings, and transmissive machinery. New ed., rev. and enl. (eighteenth impression)--pt. 2. Chiefly on engine details, by W. C. Unwin and A. L. Mellanby.