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, 2001)

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, 2020)

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

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

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, 1979)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2009)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1973)

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, 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, 1980)

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

Official lists and indexes of names and works in zoology. Supplement 1986-2000 - International Commission on Zoological Nomenclature (International Trust for Zoological Nomenclature, c/o Natural History Museum, 2001)

Ohrknorpel und äusseres ohr der Säugetiere; eine vergleichend-anatomische Untersuchung - Boas, J. E. V. (Johan Erik Vesti), 1855 -1935 ([Nielsen & Lydiche (A. Simmelkiær)], 1912)

Old bones : or, Notes for young naturalists - Brooks, Vincent, 1815? -1885 (Robert Hardwicke, 1861)

Old bones : or, Notes for young naturalists, on vertbebrate animals, their fossil predecessors and allies - Symonds, W. S. 1818 -1887 (Robert Hardwicke, 1864)

The Oligocene Hsanda Gol Formation, Mongolia : a revised faunal list - Mellett, James Silvan, 1936 - (American Museum of Natural History, 1968)

On the anatomy of vertebrates - Owen, Richard, 1804 -1892 (Longmans, Green, 1866)

On the anatomy of vertebrates ... - Owen, Richard, 1804 -1892 (Longmans, Green and Co, 1866)

On the classification and geographical distribution of the Mammalia, being a lecture on Sir Robert Reade's foundation, delivered before the University of Cambridge ... May 10, 1859. To which is added an appendix "On the gorilla," and "On the extinction and transmutation of species." - Owen, Richard, 1804 -1892 (J. W. Parker and son, 1859)

On the contents of a bone cave in the island of Anguilla (West Indies) - Cope, E. D. (Edward Drinker), 1840 -1897 (Smithsonian institution, 1883)

On the epizootology of FMD in the Ukraine caused by virus A22. Do pitannya epizootologi yashchura na Ukraini viklikanogo virusom A22 - Shcherbyna, O. K. (1978)

On the primitive types of the orders of Mammalia Educabilia - Cope, E. D. (Edward Drinker), 1840 -1897 (1873)

On the short footed ungulata of the eocene of Wyoming - Cope, E. D. (Edward Drinker), 1840 -1897 (American Philosophical Society, 1873)

On the structure and relations of Notharctus, an American eocene primate - Gregory, William K. (William King), 1876 -1970 (1920)

On the supposed presence of Miocene Tayassuidae and Dromomerycinae (Mammalia, Cetartiodactyla) in South America - Croft, Darin A. (American Museum of Natural History, 2021)

On Vertebrata from the Tertiary and Cretaceous rocks of the North West Territory - Cope, E. D. (Edward Drinker), 1840 -1897 (W.F. Brown & Co, 1891)

On vertebrata from the Tertiary and Cretaceous rocks of the North West Territory - Cope, E. D. (Edward Drinker), 1840 -1897 (W.F. Brown & Co, 1891)

On vertebrata from the tertiary and cretaceous rocks of the North West Territory. I. The species from the Oligocene or Lower Miocene beds of the Cypress hills - Cope, E. D. (Edward Drinker), 1840 -1897 (Brown, 1891)

The orders of mammals - Gregory, William K. (William King), 1876 -1970 (The Trustees, 1910)

Organic evolution considered - Fairhurst, Alfred, 1843 -1921 (Christian publishing, 1897)

The origin and affinities of the South American Condylarthra and early Tertiary Litopterna (Mammalia) - Cifelli, Richard (American Museum of Natural History, 1983)

The origin of the fittest : essays on evolution - Cope, E. D. (Edward Drinker), 1840 -1897 (D. Appleton, 1887)

The origin of the fittest : essays on evolution - Cope, E. D. (Edward Drinker), 1840 -1897 (Macmillan and Company, 1887)