 | Douglas fir Diseases and pests California. | (1) |
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 | Major outbreaks of the Douglas-fir tussock moth in Oregon and California / Boyd E. Wickman, Richard R. Mason, C.G. Thompson. Wickman, Boyd E. cn Portland Or. : Pacific Northwest Forest and Range Experiment Station, Forest Service, U.S. Dept. of Agriculture, 1973. | |
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