Notes on the birds of Damara Land and the adjacent countries of South-west Africa - Gurney, John Henry, 1819 -1890 (J. van Voorst, 1872)

Novi Commentarii Academiae Scientiarum Instituti Bononiensis - R. Accademia delle scienze dell'Istituto di Bologna. (1849)

Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1903)

Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1910)

Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1914)

Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1921)

Novorum actorum Academiae Caesareae Leopoldino-Carolinae Germanicae Naturae Curiosorum - Kaiserlich Leopoldinisch-Carolinische Deutsche Akademie der Naturforscher (Friedrich Frommann, 1864)

Nuovi annali delle scienze naturali (1843)

Nuovi annali delle scienze naturali (1847)

Nuovi annali delle scienze naturali (1851)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1863)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1870)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1873)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1912)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1913)

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

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)

Öfversigt af Finska vetenskaps-societetens förhandlingar - Suomen Tiedeseura (s.n.], 1906)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1859)

Okens Lehrbuch der Naturgeschichte - Oken, Lorenz, 1779 -1851 (Bei Carl Heinrich Reclam, 1815)

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, 1939)

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, 1945)

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, 1954)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1877)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1889)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1894)

Opuscula Ichneumonologica : Fascicule 1-45 - Schmiedeknecht, Otto, 1847 -1936 ([s.n.], 1906)

Opuscula zoologica - Zoologische Staatssammlung München. (Zoologische Staatssammlung, 1957)

The orchid hybrids. Second supplement - Hansen, Geo. (George), 1863 -1908 (Geo. Hansen, 1897)

The orchid hybrids enumeration and classification of all hybrids of orchids published up to October 15, 1895 - Hansen, Geo. (George), 1863 -1908 (Dulau, 1895)

The orchid-stud book : an enumeration of hybrid orchids of artificial origin ... : with an historical introduction ... and a chapter on hybridising and raising orchids from seed - Hurst, C. C. 1870 -1947 (F. Leslie, 1909)

Orchids: their culture and management - Watson, William, 1858 -1925 (L. U. Gill, 1903)

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, 1899)

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

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

Ornithological synonyms - Strickland, Catherine Dorcas Maule Jardine (J. Van Voorst, 1855)

The ornithological works of Arthur, ninth Marquis of Tweeddale - Wardlaw Ramsay, R. G. (Robert George), 1852 -1921 (Taylor and Francis, 1881)