Não informado. (1950). Forest Resource Report. U.S. Department of Agriculture, Forest Service.
Chicago-referens (17:e uppl.)Não informado. Forest Resource Report. Washington: U.S. Department of Agriculture, Forest Service, 1950.
MLA-referens (8:e uppl.)Não informado. Forest Resource Report. U.S. Department of Agriculture, Forest Service, 1950.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.