Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1932)

Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1933)

Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1937)

Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1938)

Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1939)

Nursery practice for trees and shrubs suitable for planting on the prairie-plains - Engstrom, H. E. (Harold Edwin), 1909 - (U.S. Dept. of Agriculture, 1941)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1897)

Occasional papers - Boston Society of Natural History. (1904)

Occasional papers - Texas Tech University. Museum, (The Museum, 1979)

Occasional papers - Texas Tech University. Museum, (The Museum, 1982)

Occasional papers - Texas Tech University. Museum, (The Museum, 1983)

Occasional papers - Texas Tech University. Museum, (The Museum, 1986)

Occasional papers - Texas Tech University. Museum, (The Museum, 1988)

Occasional papers - Texas Tech University. Museum, (The Museum, 1989)

Occasional papers - Texas Tech University. Museum, (The Museum, 1991)

Occasional papers - Texas Tech University. Museum, (The Museum, 1992)

Occasional papers - Texas Tech University. Museum, (The Museum, 2002)

Occasional papers - Texas Tech University. Museum, (The Museum, 2003)

Occasional papers - Texas Tech University. Museum, (The Museum, 2004)

Occasional papers - Texas Tech University. Museum, (The Museum, 2020)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1904)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1922)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2010)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1974)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1975)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1978)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1979)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1984)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1989)

Occasional papers of the Museum of Zoology, University of Michigan - University of Michigan. Museum of Zoology. (University of Michigan, 1918)

Occasional papers of the Natural History Museum, the University of Kansas, Lawrence, Kansas - University of Kansas. Museum of Natural History. (The University, 1996)

Occasional papers - Tulane University. Museum of Natural History. (The Museum, 1982)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1892)

The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1909)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1910)

The Ohio recent mammal collection in the Cleveland museum of natural history - Cleveland Museum of Natural History ([Cleveland Museum of Natural History], 1942)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1936)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1952)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1973)

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

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1986)

Okens Lehrbuch der Naturgeschichte - Oken, Lorenz, 1779 -1851 (Bei Carl Heinrich Reclam, 1816)

On Balantidium coli (Malmsten) and Balantidium suis (sp. nov.) with an account of their neuromotor apparatus - McDonald, James Daley, 1892 - (University of California press, 1922)

On the batrachia and reptilia of Costa Rica : With notes on the herpetology and ichthyology of Nicaragua and Peru - Cope, E. D. (Edward Drinker), 1840 -1897 (s.n, 1875)

On the biology and systematic position of Microtus abbreviatus Miller, a vole endemic to the St. Matthew Islands, Bering Sea - Rausch, V R (1968)

The Ontario natural science bulletin - Wellington Field Naturalists' Club. (Wellington Field Naturalists' Club, 1909)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank H. Lattin, 1904)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank H. Lattin, 1905)

Ootheca Wolleyana: an illustrated catalogue of the collection of birds' eggs - Newton, Alfred, 1829 -1907 (sold by R. H. Porter, 1907)

Ein ornithologischer Ausflug nach den Seen Saissan-nor und Marka-kul (in West-Sibirien) im Jahre 1909 - Poljakov, G. I. (1912)

Ornithologisches Jahrbuch (V. Tschusi, 1904)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1898)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1900)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1901)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1907)

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

Otters and otter-hunting - Duncombe-Jewell, Ludovick Charles Richard 1866 - (L. Upcott Gill, 1908)

Our country's animals and how to know them. A guide to the mammals, reptiles and amphibians of Great Britain - Gordon, W. J. (Simpkin, Marshall, Hamilton, Kent, 1904)

Outlines of economic zoölogy - Reese, A. M. (Albert Moore), 1872 -1965 (P. Blakiston's Son & Co, 1919)

Pacific science - University of Hawaii. (University Press of Hawaii, 1954)

Pacific science - University of Hawaii. (University Press of Hawaii, 1961)

Paleontological investigations at Mineral Hill Cave - Broughton, Jack M. (U.S. Department of the Interior, Bureau of Land Management, Elko Field Office, 2004)

Palsas in Baker Creek Basin N.W.T. : an ecosystematic study - Luff, David Owen. (University of Alberta, Dept. of Geography, 1978)

Pamphlets on forestry in Kansas (1900)

Pamphlets on forestry in West Virginia (1900)

Pamphlets on silviculture (1899)

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

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1958)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1962)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1984)

Papers concerning the palæontology of California, Arizona, and Idaho - Merriam, John C. (John Campbell), 1869 -1945 (Carnegie Institution of Washington, 1934)

Papers in vertebrate paleontology honoring Robert Warren Wilson - Carnegie Museum of Natural History (Carnegie Museum of Natural History, 1984)

Papers on mammalogy - Field Museum of Natural History. (Field Museum of Natural History, 1941)

Parasitology - British Society for Parasitology. (Cambridge University Press, 1914)

Parasitology (Cambridge University Press, 1922)

A Partial bibliography of the mammals of Wyoming and adjacent states with special reference to density and habitat affinity - United States. Bureau of Land Management. (Wyoming Game & Fish Department, 1978)

Pattedyr - Winge, H. (Herluf) (Forlagt af G.E.C. Gad, 1908)

Patterns in the structure of mammalian communities - Morris, Douglas W. (Texas Tech University Press, 1989)