Não informado. (1963). US Forest Service Research Paper PNW. U.S. Forest Service.
Chicago-viite (17. p.)Não informado. US Forest Service Research Paper PNW. Portland, Ore: U.S. Forest Service, 1963.
MLA-viite (8. p.)Não informado. US Forest Service Research Paper PNW. U.S. Forest Service, 1963.
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