http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
proceedings of IUFRO Conference, Minneapolis-St. Paul, USA, September 1973
International Union of Forestry Research Organizations
USDA Forest Service, Northeastern Forest Experiment Station
compiled by D. A. Burdekin and H. M. Heybroek.