 | Cone crops of ponderosa pine in central Arizona | (1) |
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 | Cone crops of ponderosa pine in central Arizona, including the influence of Abert squirrels / by M.M. Larson and Gilbert H. Schubert. Larson, M. M. (Merlyn Milfred), 1928- Fort Collins, Colo. : Rocky Mountain Forest and Range Experiment Station, Forest Service, U.S. Dept. of Agriculture, 1970. | |
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