"United States. Forest Service." . . "Logging." . . "Oregon." . . "Logging Oregon." . . "Pacific Northwest Forest and Range Experiment Station (Portland, Or.)" . . . . "Slash (Logging)" . . "Douglas fir." . . . . . "Characteristics of residues in a helicopter logged area of old-growth Douglas-fir"@en . "Characteristics of residues in a helicopter logged area of old-growth Douglas-fir" . . . . . . . . "Statistics"@en . . . . . . . . . . . . . . . . .