Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1880)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1981)

Old growth in northwestern California national forests - Pacific Northwest Research Station (Portland, Or.) (U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station, 1996)

Oleoresin production : a microscopic study of the effects produced on the woody tissues of southern pines by different methods of turpentining - Gerry, Eloise, 1885 -1970 (U.S. Dept. of Agriculture, 1922)

On the campus; addresses delivered at various times before university and college audiences - Macbride, Thomas H. (Thomas Huston), 1848 -1934 (The Torch Press, 1916)

On the geology and natural history of the upper Missouri :Being the substance of a report made to Lieut. G.K. Warren, T.E. U.S.A - Hayden, F. V. (Ferdinand Vandeveer), 1829 -1887 (Printed by C. Sherman & son, 1862)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank H. Lattin, 1919)

Opportunities for increasing water yields and other multiple use values on ponderosa pine forest lands - Brown, Harry E. (Harry Esmond), 1924 - (Rocky Mountain Forest and Range Experiment Station, Forest Service, U.S. Dept. of Agriculture, 1974)

Opportunities for timber management and wood utilization of the mixed conifer type in Arizona and New Mexico - Rocky Mountain Forest; Range Experiment Station (Fort Collins, Colo.) (Rocky Mountain Forest and Range Experiment Station, Forest Service, U.S. Dept. of Agriculture, 1984)

Optimal sites for seedlings of ten conifers - University of Alberta. Dept. of Agricultural Engineering. (1977)

Opuscula philolichenum (J. Lendemer, 2016)

Opuscula philolichenum (J. Lendemer, 2017)

Opuscula philolichenum (J. Lendemer, 2021)

Orchard and garden (J.T. Lovett, 1889)

Orchidaceae: illustrations and studies of the family Orchidaceae - Ames, Oakes, 1874 -1950 (Houghton, Mifflin, 1910)

Orchidacearum genera et species. Vol.1-[2, pars 1] - Kraenzlin, Fritz, 1847 -1934 (Mayer & Müller, 1901)

Orcutt Seed and Plant Company : trade price list 1889-1890 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Orcutt Seed and Plant Company, 1889)

[Order forms] - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Woodlot Seed Co, 1958)

Oregon flora newsletter - Oregon State University. Department of Botany; Plant Pathology. (Oregon Flora Project, Dept. of Botany & Plant Pathology, Oregon State University, 2011)

Oregon greater sage-grouse : draft resource management plan amendment and environmental impact statement - United States. Bureau of Land Management. Oregon State Office. (U.S. Department of the Interior, Bureau of Land Management, Oregon State Office, 2018)

Oregon greater sage-grouse : draft supplemental environmental impact statement - United States. Bureau of Land Management. (U.S. Department of the Interior, Bureau of Land Management, Oregon State Office, 2020)

Oregon greater sage-grouse : final supplemental environmental impact statement - United States. Bureau of Land Management. (U.S. Department of the Interior, Bureau of Land Management, Oregon State Office, 2020)

Origin and history of all the pharmacopeial vegetable drugs, chemicals and preparations with bibliography... Prepared under the auspices of and pub. by the American drug manufacturers' association, Washington, D.C - Lloyd, John Uri, 1849 -1936 (The Caxton press, 1921)

Ornamental and fruit trees, shrubs, roses, etc - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (J. Wragg & Sons Co, 1900)

Ornamental trees and shrubs price list : spring 1930 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Joseph B. Gable, 1930)

Ornamental trees and shrubs price list : spring 1931 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Joseph B. Gable, 1931)

Ornamental trees, evergreens and shrubs, roses, bulbs, fruit trees, lawn grasses - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Lakewood Nurseries, 1926)

Ornamental trees, evergreens, windbreaks, fruits, shrubs : spring 1947 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (J.V. Bailey Nurseries, 1947)

Ornamental trees, evergreens, windbreaks, fruits, shrubs : spring 1945 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (J.V. Bailey Nurseries, 1945)

Ornamental trees, shrubs, and woody climbers - Macoun, W. T. (William Tyrrell), 1869 -1933 (Canada Dept. of Agriculture, 1927)

Ornithological report upon collections made in portions of California, Nevada, and Oregon - Henshaw, Henry W. (Henry Wetherbee), 1850 -1930 (1879)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1899)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1917)

Our living resources : a report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems - United States. National Biological Service. (U.S. Dept. of the Interior, National Biological Service, 1995)

Our national parks - Muir, John, 1838 -1914 (Houghton, Mifflin and Company, 1901)

Our native birds of song and beauty, being a complete history of all the songbirds, flycatchers, hummingbirds, swifts, goatsuckers, woodpeckers, kingfishers, trogons, cuckoos, and parrots, of North America - Nehrling, Henry, 1853 -1929 (G. Brumder, 1893)

Our trees, how to know them : photographs form nature by Arthur I. Emerson, with a guide to their recognition at any season of the year and notes on their characteristics, distribution, and culture, by Clarence M. Weed - Weed, Clarence Moores, 1864 -1947 (J.B. Lippincott Company, 1918)

Our trees, how to know them; photographs from nature - Weed, Clarence Moores, 1864 -1947 (Lippincott, 1936)

Our trees, how to know them: photographs from nature by Arthur I. Emerson, with a guide to their recognition at any season of the year and notes on their characteristics, distribution, and culture - Weed, Clarence Moores, 1864 -1947 (J.B. Lippincott, 1918)

An outline of plant geography (The Macmillan company, 1926)

Outlines of botany for the high school laboratory and classroom (based on Gray's Lessons in botany) - Leavitt, Robert Greenleaf, 1865 - (American Book Co, 1901)

Outlines of course of instuction in agricultural nature study for the rural schools of California - California Agricultural Experiment Station. (1923)

Outlines of forestry - Houston, Edwin J. (Edwin James), 1847 -1914 (J. B. Lippincott company, 1893)

Outlines of forestry : or, The elementary principles underlying the science of forestry : being a series of primers of forestry - Houston, Edwin J. (Edwin James), 1847 -1914 (J. B. Lippincott, 1893)

Outlines of forestry : or, The elementary principles underlying the science of forestry : being a series of primers of forestry - Houston, Edwin J. (Edwin James), 1847 -1914 (J.B. Lippincott, 1893)

Overstory removal and residue treatments affect soil surface, air, and soil temperature : implications for seedling survival - Intermountain Research Station (Ogden, Utah) (U.S.D.A. Forest Service, Intermountain Research Station, 1987)

Pacific Northwest ecoclass codes for plant associations - Hall, Frederick C. (USDA, Forest Service, Pacific Northwest Region, 1988)

Pamphlets on forest protection (1900)

Pamphlets on forest utilization (1900)

Pamphlets on forestry (1900)

Pamphlets on forestry. Grazing (1900)

Pamphlets on forestry. History (1900)

Pamphlets on forestry in California (1900)

Pamphlets on forestry in Canada (1900)

Pamphlets on forestry in Colorado (1900)

Pamphlets on forestry in Great Britain (1900)

Pamphlets on forestry in Kansas (1900)

Pamphlets on forestry in Minnesota (1900)

Pamphlets on forestry in Montana (1900)

Pamphlets on forestry in Nebraska (1900)

Pamphlets on forestry in North Dakota and South Dakota (1900)

Pamphlets on forestry in Ohio (1900)

Pamphlets on forestry in Pennsylvania (1900)

Pamphlets on forestry in Texas (1900)

Pamphlets on silviculture (1899)

Pamphlets on the lumber industry (1900)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1925)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1926)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1927)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1929)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1930)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1931)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1932)