Nuovi annali delle scienze naturali (1851)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1838)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1864)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1920)

Observationes Zoologicae : quibus novae complures, aliaeque animalium species describuntur et illustrantur - Hermann, Johannis. (Amandum Koenig, 1804)

Observations on the geology and zoology of Abyssinia, made during the progress of the British expedition to that country in 1867-68 - Blanford, W. T. (William Thomas), 1832 -1905 (Macmillan and co, 1870)

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)

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

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

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1921)

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, 1899)

Occasional papers of the Museum of Zoology, University of Michigan - University of Michigan. Museum of Zoology. (University of Michigan, 1922)

Œuvres complètes de Buffon - Buffon, Georges Louis Leclerc, comte de, 1707 -1788 (Chez F.D. Pillot, 1831)

Œuvres complètes de Buffon avec la nomenclature Linnéenne et la classification de Cuvier - Buffon, Georges Louis Leclerc, comte de, 1707 -1788 (1853)

Official checklist of the birds of Australia compiled by the Checklist Committee, Royal Australasian Ornithologists Union ; with appendix, scientific names–notes and pronunciation - Royal Australasian Ornithologist's Union. Checklist Committee (H.J. Green, Govt. Printer, 1926)

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 Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1844)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1848)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1850)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1851)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1869)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1898)

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, 1935)

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, 1938)

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, 1943)

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, 1946)

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

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, 1976)

Les Oiseaux d'Europe décrits par C. J. Temminck - Werner, Johann Carl. (1848)

Les oiseaux d'Europe, tableaux synoptiques - Paris, Paul, 1875 -1938. (L. Laveur, 1906)

Les oiseaux de l'est du Canada - Taverner, P. A. (Percy Algernon), 1875 -1947 (F.A. Acland, 1922)

Les oiseaux de l'Europe et leurs oeufs, décrits et dessinés dáprès nature - Dubois, Alphonse, 1839 -1921. (Chez C. Muquardt, 1872)

Les oiseaux de l'Europe et leurs oeufs, décrits et dessinés d'après nature - Dubois, Alphonse, 1839 -1921. (chez C. Muquardt, 1872)

Les oiseaux de la province de Que´bec - Dionne, C.-E. (Charles-Eusèbe), 1846 -1925 (Dussault & Proulx, 1906)

Les oiseaux des phosphorites du Quercy - Gaillard, Claude, 1861 -1945 (A. Rey; [etc., etc.], 1908)

Les oiseaux du Canada - Dionne, C.-E. (Charles-Eusèbe), 1846 -1925 (s.n.], 1883)

Les oiseaux du Canada - Dionne, C.-E. (Charles-Eusèbe), 1846 -1925 (P. G. Delisle, 1883)

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

Oiseaux voyageurs et poissons de passage. Étude comparée d'organisme, de moeurs et d'instinct - Berthelot, Sabin, 1794 -1880 (Challamel aîné, 1875)

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

On a collection of birds from North-Eastern Abyssinia and the Bogos Country - Jesse, William. (Zoological Society of London, 1870)

On a second collection of birds from Tongoa, New Hebrides - Collett, Robert, 1842 -1913 (1898)

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)

Onomasticon zoicon, plerorumque animalium differentias & nomina propria pluribus linguis exponens : cui accedunt Mantissa anatomica, et quaedam De variis fossilium generibus - Charleton, Walter, 1619 -1707 (Apud Jacobum Allestry ..., 1668)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank H. Lattin, 1887)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank H. Lattin, 1888)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank H. Lattin, 1902)

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, 1909)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank H. Lattin, 1912)

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

Ootheca Wolleyana: an illustrated catalogue of the collection of birds' eggs - Newton, Alfred, 1829 -1907 (sold by R. H. Porter, 1905)

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)

The Oregon naturalist (Naturalist Pub. Co, 1895)

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, 1889)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1890)

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

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1895)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1898)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1899)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1905)

Ornis Caucasica. Die Vogelwelt des Kaukasus : systematisch und biologisch-geographisch beschrieben - Radde, Gustav, 1831 -1903 (Verlag von Theodor Fischer, 1884)

Ornithologia methodice digesta, atque iconibus aeneis ad vivum illuminatis ornata - Lorenzi, Lorenzo. (In Aedibus Mouchianis, 1767)

Ornithologia methodice digesta, atque iconibus aeneis ad vivum illuminatis ornata - Lorenzi, Lorenzo. (In Aedibus Mouchianis, 1771)

Ornithologia methodice digesta, atque iconibus aeneis ad vivum illuminatis ornata - Lorenzi, Lorenzo. (In Aedibus Mouchianis, 1773)

Ornithologia methodice digesta, atque iconibus aeneis ad vivum illuminatis ornata - Lorenzi, Lorenzo. (In Aedibus Mouchianis, 1776)

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)