http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Driver understanding of work zone flagger signals and signaling devices
by Stephen H. Richards, Nada D. Huddleston and Janet D. Bowman.
Sponsored by the Texas State Dept. of Highways and Public Transportation in cooperation with the Federal Highwy Administration.