http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Agricultural Research Center (Beltsville, Md.)
[developed by Joan Valieant and Jerry L. Southland ; prepared by Information Division, Agricultural Research Service].
"Issued October 1971; slightly revised January 1972"--page 12.