Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1991)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1900)

Oil spill sensitivity of the western Indian Ocean islands: coastal data from the Comoros Islands, Madagascar, Mauritius, Reunion and the Seychelles - Green, Edmund P. (Edmund Peter) 1965 - (WCMC, 1998)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1954)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1960)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1964)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1965)

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, 1974)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1976)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1977)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1978)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1988)

Les oiseaux de la Suisse (Catalogue des oiseaux de la Suisse de V. Fatio et Th. Studer) élaboré par ordre du Département fédéral de l'intérieur (Inspection des forêts, chasse et pêche) - Fatio, Victor, 1838 -1906 (1901)

Oiseaux - Fédération des sociétés françaises de sciences naturelles. Office central de faunistique. (P. Lechevalier, 1921)

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

On the intestinal tract of birds; with remarks on the valuation and nomenclature of zoological characters - Mitchell, P. Chalmers Sir, (Peter Chalmers), 1864 -1945 (1901)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank H. Lattin, 1909)

Oologia neerlandica : eggs of birds breeding in the Netherlands - Lechner, Arnold Anthon van Pelt (Nijhoff, 1911)

The oologists' hand-book : 1885 catalogue of American birds' eggs, and oological supplies, with prices at which they may be obtained of - Lattin, Frank H (John P. Smith, Printer, 1885)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1885)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1886)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1887)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1888)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1891)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1904)

Ornithological bibliography - Coues, Elliott, 1842 -1899 (Geological Survey [etc.], 1878)

Ornithological gazetteer of Argentina - Paynter, Raymond A. Jr. (Obtainable from Bird Dept., Museum of Comparative Zoology, Harvard University, 1995)

Ornithological gazetteer of Brazil - Traylor, Melvin A. (Melvin Alvah), 1915 -2008 (Obtainable from Bird Dept., Museum of Comparative Zoology, Harvard University, 1991)

Ornithological gazetteer of Chile - Paynter, Raymond A. Jr. (Bird Dept., Museum of Comparative Zoology, Harvard University, 1988)

Ornithological gazetteer of Colombia - Paynter, Raymond A. Jr. (Bird Dept., Museum of Comparative Zoology, Harvard University, 1997)

An ornithological index, arranged according to the synopsis avium of Mr. Vigors / by T. B. L. Baker - Vigors, N. A.‏ ‎ (Nicholas Aylward),‏ ‎ 1785 -1840 (Printed by R. Taylor, 1835)

Ornithological science - Nihon Chogakkai (Ornithological Society of Japan, 2002)

Ornithologie Nordost-Afrika's : der Nilquellen- und Küsten Gebiete des Rothen Meeres und des nördlichen Somal-Landes - Heuglin, Theodor von, 1824 -1876 (T. Fischer, 1869)

Ornithologie Nordost-Afrika's : der Nilquellen- und Küsten Gebiete des Rothen Meeres und des nördlichen Somal-Landes - Heuglin, Theodor von, 1824 -1876 (T. Fischer, 1871)

Ornithologie Nordost-Afrika's : der Nilquellen- und Küsten Gebiete des Rothen Meeres und des nördlichen Somal-Landes - Heuglin, Theodor von, 1824 -1876 (T. Fischer, 1874)

Ornithologie Nordost-Afrika's : der Nilquellen- und Küsten Gebiete des Rothen Meeres und des nördlichen Somal-Landes - Heuglin, Theodor von, 1824 -1876 (T. Fischer, 1873)

Ornithologische Beobachtungen : grösstentheils im Sommer 1869 auf einer Reise im Nordwestlichen Russland - Mewes, W. (C. Gerold's Sohn, 1886)

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1893)

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1894)

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1895)

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1897)

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1899)

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1902)

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1907)

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1912)

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1913)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1901)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1906)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1907)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1912)

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

Ornithologisches Centralblatt (L.A. Kittler, 1876)

Ornithologisches Centralblatt (L.A. Kittler, 1879)

Ornithologisches Jahrbuch (V. Tschusi, 1892)

Ornithologisches Jahrbuch (V. Tschusi, 1898)

Ornithologisches Jahrbuch (V. Tschusi, 1909)

Ornithology and oölogy of New England: containing full descriptions of the birds of New England, and adjoining states and provinces ... - Samuels, Edward A. (Edward Augustus), 1836 -1908 (Nichols and Noyes, 1867)

The ornithology of Illinois - Ridgway, Robert, 1850 -1929 (H.W. Rokker, printer, 1889)

The ornithology of Illinois - Ridgway, Robert, 1850 -1929 (H. W. Rokker, printer, 1889)

Ornitologia della Papuasia e delle Molucche - Salvadori, Tommaso, 1835 -1923 (G.B. Paravia, 1880)

Ornitologia della Papuasia e delle Molucche : parte prima-[terza] - Salvadori, Tommaso, 1835 -1923 (Stamperia reale G.B. Paravia e co. di I. Vigliardi, 1880)

The Osprey (The Osprey Co, 1900)

Osteology of birds - Shufeldt, Robert Wilson 1850 -1934 (University of the State of New York, 1909)

O.S.U. naturalist - Ohio State University. Biological Club. (Biological Club of Ohio State University, 1901)

Our common birds and how to know them - Grant, John Beveridge (C. Scribner, 1895)

Our common birds and how to know them - Grant, John Beveridge (C. Scribner's sons, 1895)

Our common cuckoo and other cuckoos and parasitical birds : an attempt to reach a true theory of them by comparative study of habit and function : with a thorough criticism and exposure of Darwin's views and Romane's views and those of their followers - Darwin, Charles, 1809 -1882 (T. Burleigh, 1899)

Our northern and eastern birds : containing descriptions of the birds of the northern and eastern states and British provinces; together with a history of their habits, times of arrival and departure, their distribution, food, song, time of breeding, and a careful and accurate description of their nests and eggs - Samuels, Edward A. (Edward Augustus), 1836 -1908 (R. Worthington, 1883)

Over vogels van Deli (Sumatra) - Heyst, A. F. C. A. van (1919)

Oversigt af Christiania omegns ornithologiske fauna - Collett, Robert, 1842 -1913 (J. Dahl, 1864)

Pacific coast avifauna - Cooper Ornithological Club. (Cooper Ornithological Club, 1909)

Pacific coast avifauna - Cooper Ornithological Club. (Cooper Ornithological Club, 1912)

Pacific coast avifauna - Cooper Ornithological Club. (Cooper Ornithological Club, 1914)

Pacific coast avifauna - Cooper Ornithological Club. (Cooper Ornithological Club, 1917)

Paleognathous birds from the early Tertiary of the northern hemisphere - Nuttall Ornithological Club. (Nuttall Ornithological Club, 1988)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1918)

Pamphlets on forestry in West Virginia (1900)

Die Papageien - Finsch, O. (Otto), 1839 -1917 (Brill, 1867)

Papéis avulsos do Departamento de Zoologia - São Paulo Departamento de Zoologia (A Secretaria, 1943)

Papéis avulsos do Departamento de Zoologia - São Paulo Departamento de Zoologia (A Secretaria, 1944)

Papéis avulsos do Departamento de Zoologia - São Paulo Departamento de Zoologia (A Secretaria, 1945)

Papéis avulsos do Departamento de Zoologia - São Paulo Departamento de Zoologia (A Secretaria, 1948)

Papéis avulsos do Departamento de Zoologia - São Paulo Departamento de Zoologia (A Secretaria, 1952)

Papers from the Hopkins-Stanford Galapagos expedition, 1898-1899 - Hopkins-Stanford Galapagos Expedition, 1898-99. (The Academy, 1901)

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

P.D. Skaar's Montana bird distribution - Montana Natural Heritage Program. (Montana Natural Heritage Program, 2012)

P.D. Skaar's Montana bird distribution - Bergeron, Dwight. (Montana Natural Heritage Program, 1992)

P.D. Skaar's Montana bird distribution - Skaar, Palmer David. (Montana Natural Heritage Program, 1996)

Pennsylvania bird life; a manual of the birds of Pennsylvania; treating especially of their food, from examinations of several thousand stomachs, made during all seasons of the year, with descriptions of the birds, their nests, eggs and habits - Warren, Benjamin Harry, 1858 -1926 (Penn'a., Pub by the author, 1892)

Per una classificazione elementare dei Passercei, Rampicanti e Trogoni, raccolta e ordinamento di alcuni caratteri - Cavazza, Filippo. (Tipografia di Paolo Neri, 1909)

Periódico zoológico - Sociedad Entomológica Argentina. (Sociedad Entomica Argentina, 1874)

Perú: Cordillera Escalera-Loreto - Stotz, Douglas F. (Douglas Forrester), 1956 - (The Field Museum, Science and Education, 2014)

Peru : Ere-Campuya-Algodón - Field Museum of Natural History. (The Field Museum, Science and Education, 2013)

Peru : Maijuna - Alverson, William Surprison (Field Museum, Environment, Culture and Conservation, 2010)

Perú : Cerros de Kampankis - Stotz, Douglas F. (Douglas Forrester), 1956 - (The Field Museum, Environment, Culture, and Conservation, 2012)

Perú, Medio Putumayo-Algodón - Stotz, Douglas F. (Douglas Forrester), 1956 - (Field Museum of Natural History, 2016)

Perú : Nanay-Mazán-Arabela - Alverson, William Surprison (Field Museum, Environmental and Conservation Programs, 2007)

Perú : Tapiche-Blanco - Field Museum of Natural History. (The Field Museum, 2015)

Perú : Yaguas-Cotuhé - Field Museum of Natural History. (Field Museum, Environment, Culture, and Conservation, 2011)

Pet birds of Bengal - Law, Satya Churn. (Thacker, Spink & Co, 1923)

Philippine birds - Du Pont, John E. (John Eleuthère), 1938 -2010 ([Delaware Museum of Natural History], 1971)