Observations on the natural affinities that connect the orders and families of birds: togethers with description of a new species of scolopax ... with observations on the anas glocitans of pallas and a description of the female of that species - Vigors, N. A.‏ ‎ (Nicholas Aylward),‏ ‎ 1785 -1840 (Richard Taylor, 1825)

Œuvres complètes de Buffon - Buffon, Georges Louis Leclerc, comte de, 1707 -1788 (Chez F.D. Pillot, 1830)

Oeuvres complètes de Christiaan Huygens. Publiées par la Société hollandaise des sciences - Huygens, Christiaan, 1629 -1695 (M. Nijhoff, 1888)

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)

Official lists and indexes of names and works in zoology - International Commission on Zoological Nomenclature (ICZN, 1987)

Öfversigt af Finska vetenskaps-societetens förhandlingar - Suomen Tiedeseura (s.n.], 1902)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1854)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1871)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1932)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1934)

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, 1939)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1941)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1944)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1955)

Les oiseaux - Perrier, Edmond, 1844 -1921 (J.B. Bailli, 1904)

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

On safari : big game hunting in British East Africa, with studies in bird-life - Chapman, Abel, 1851 -1929 (Longmans, Green, 1908)

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 natural history and classification of birds - Swainson, William, 1789 -1855 (John Taylor, 1836)

On the Natural History and classification of Birds : vol. I and II - Swainson, William, 1789 -1855 (pr. for Longman [etc.], 1836)

Onze vogels in huis en tuin - Keulemans, J. G. (John Gerrard), 1842 -1912 (P.W.M. Trap, 1869)

Opera ornithologica - Bonaparte, Charles-Lucien, 1803 -1857 (1857)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1916)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1955)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1956)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1958)

The Orchid world. A monthly illustrated journal entirely devoted to orchidology - Wilson, Gurney, 1878 - (Alabaster, Passmore & Sons, ltd., printers], 1913)

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)

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

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

Ornithologia, or, The birds: a poem, in two parts : with an introduction to their natural history; and copious notes - Jennings, James. (Sherwood, Gilbert, and Piper, 1829)

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

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 miscellany - Mintern Bros., (Trübner and Co., Bernard Quaritch, R.H. Porter, 1877)

Ornithologie d'Angola. Ouvrage publié sous les auspices du Ministere de la Marine et des Colonies - Barbosa du Bocage, J. V. (José Vicente), 1823 -1908 (Imprimerie Nationale, 1881)

Ornithologie européenne, ou, Catalogue descriptif, analytique et raisonné des oiseaux observés en Europe - Gerbe, Zéphirin, 1810 -1890 (J.B. Bailli, 1867)

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, 1873)

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)

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, 1894)

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

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1898)

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

Ornithologische Monatsberichte (Verlag von R. Friedländer & Sohn, 1900)

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

Ornithologischer Beitrag zur Fauna Madagascar's. Mit Berücksichtigung der Inseln Mayotta, Nossi-Bé und St. Marie, sowie der Mascarenen und Seychellen - Hartlaub, Gustav, 1814 -1900 (C. Schünemann, 1861)

Ornithologisches Centralblatt (1880)

Ornithologisches Centralblatt (L.A. Kittler, 1878)

Ornithologisches Centralblatt (1881)

Ornithology - Jardine, William, 1800 -1874 (W.H. Lizars, 1853)

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, 1913)

Ornithology : the natural history of birds : third-book of natural history prepared for the use of schools and colleges - Comté, Achille, 1802 -1866 (Turner & Fisher, publishers, 1842)

The Osprey (The Osprey Co, 1900)

Osteologia avium, or, A sketch of the osteology of birds - Brooks, Vincent, 1815? -1885 (Published by R. Hobson, Wellington, Salop, 1867)

Osteologia avium, or, A sketch of the osteology of birds - Brooks, Vincent, 1815? -1885 (Published by R. Hobson, Wellington, Salop, 1875)

Osteologia avium : or a sketch of the osteology of birds - Eyton, T. C. (Thomas Campbell), 1809 -1880 (Salop, R. Hobson)

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

Osteology of living and fossil new world quail - Holman, J. Alan, 1931 -2006 (1961)