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)

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)

Opuscula medica, quae reperiri potuere omnia, nunc primo simul edita - Drelincourt, Charles, 1633 -1697 (Apud Alberts & van der Kloot, 1727)

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

Organization of repetitive DNA in the primitive reptile (Sphenodon Punctatus) - Van Den Bussche, Ronald A. (Museum of Texas Tech University, 1998)

The origin of human reason, being an examination of recent hypotheses concerning it - Mivart, St. George Jackson, 1827 -1900 (K. Paul, Trench, 1889)

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)

The origin of the human capacity - Tattersall, Ian (American Museum of Natural History, 1998)

Le origini umane; ricerche paleontologiche - Sergi, Giuseppe, 1841 -1936 (Fratelli Bocca, 1913)

Der Ornithologische Beobachter - Ala, Schweizerische Gesellschaft für Vogelkunde und Vogelschutz. (Ala, Schweizerische Gesellschaft für Vogelkunde und Vogelschutz, 1905)

Der Ornithologische Beobachter - Ala, Schweizerische Gesellschaft für Vogelkunde und Vogelschutz. (Ala, Schweizerische Gesellschaft für Vogelkunde und Vogelschutz, 1913)

The Ornithologist and oölogist (1884)

Orthoptera of northeastern America : with especial reference to the faunas of Indiana and Florida - Blatchley, W. S. (Willis Stanley), 1859 -1940 (Nature Pub. Co., 1920, 1920)

Ortus sanitatis - Prüss, Johann, 1446 or 1447 -1510 (J. Prüss)

The os navicular of humans, great apes, OH 8, Hadar, and Oreopithecus : function, phylogeny, and multivariate analysis - Marcus, Leslie Floyd, 1930 -2002 (American Museum of Natural History, 2000)

Our face from fish to man; a portrait gallery of our ancient ancestors and kinsfolk together with a concise history of our best features - Gregory, William K. (William King), 1876 -1970 (G.P. Putnam's Sons, 1929)

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 ; with illustrations of many species of the birds and accurate figures of their eggs - Samuels, Edward A. (Edward Augustus), 1836 -1908 (R. Worthington, 1883)

The outline of science : a plain story simply told - Thomson, J. Arthur (John Arthur), 1861 -1933 (G. P. Putnam's sons, 1922)

Outlines of evolutionary biology - Dendy, Arthur, 1865 -1925 (D. Appleton and company, 1914)

Outlines of general zoology - Baird, Spencer Fullerton, 1823 -1887 (Rudolph Garrigue, 1851)

Outlines of the history of botany - Harvey-Gibson, R. J. (Robert John), 1860 -1929 (Black, 1919)

Outlines of the history of botany - Harvey-Gibson, R. J. (Robert John), 1860 -1929 (A.& C. Black, 1919)

Outlines of vertebrate palæontology for students of zoology - Woodward, Arthur Smith, 1864 -1944 (University Press, 1898)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (Humphrey Milford, Oxford University Press, 1929)

Oversigt over det Kongelige Danske videnskabernes selskabs forhandlinger = Bulletin de l'Académie royale des sciences et des lettres de Danemark - Kongelige Danske videnskabernes selskab. (A.F. Høst, 1900)

P. Boddaert, med. doct. urbis Ulissingæ exconsiliarii ... Elenchus animalium, volumen I : sistens quadrupedia huc usque nota, eorumque varietates : ad ductum naturae, quantum fieri potuit disposita - Boddaert, Pieter, 1730 -1795 (Apud C.R. Hake, 1784)

Palaeontographia Italica : Memorie di paleontologia - Canavari, Mario 1855 -1928 (Tip. T. Nistri, 1919)

Palaeontographica (Theodor Fischer, 1913)

Palaeontographica Americana - Paleontological Research Institution (Ithaca, N.Y.) (Paleontological Research Institution, 1956)

Palaeontology; or, A systematic summary of extinct animals and their geological relations - Owen, Richard, 1804 -1892 (A. and C. Black, 1860)

Palaeontology; or, A systematic summary of extinct animals and their geological relations - Owen, Richard, 1804 -1892 (A. and C. Black, 1861)

Palaeontology or A systematic summary of extinct animals and their geological relations - Owen, Richard, 1804 -1892 (A. and C. Black, 1861)

Palaeontology, or, A systematic summary of extinct animals and their geological relations - Owen, Richard, 1804 -1892 (A. and C. Black, 1860)

Palaozoologie : Entwurf einer systematischen Darstellung der Fauna der Vorwelt - Giebel, C. (Christoph), 1820 -1881 (Nulandt'sche buchandlung (L. Garcke), 1846)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1973)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1974)

Papers and proceedings of the Royal Society of Tasmania - Royal Society of Tasmania. (The Society, 1894)

Papers and proceedings of the Royal Society of Tasmania - Royal Society of Tasmania. (The Society, 1920)

Papers and proceedings of the Royal Society of Tasmania - Royal Society of Tasmania. (The Society, 1921)

Papers, chiefly anatomical, presented at the Portland Meeting of the American Association for the Advancement of Science, August 1873 - American Association for the Advancement of Science. (Salem Press, 1874)

Papers presented at the Celebration of the Twentieth Anniversary of the New York Botanical Garden, September 6-9, 1915. Published by the aid of the David Lydig Fund, bequethed by Charles P. Daly - New York Botanical Garden (1916)

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

Pestmegye és tájéka viránya - Gönczy, Pál, 1817 -1892 (Magyar Királyi Egyetemi Nyomda Sajátja, 1879)

Petrefacten-Buch oder allgemeine und besondere Versteinerungskunde : mit Berücksichtigung der Lagerungsverhältnisse, besonders in Deutschland - Schmidt, F. A. (Hoffmann'sche Verlags-Buchhandlung, 1846)

Petrefactenbuch, oder allgemeine und besondere Versteinerungskunde mit Berücksichtigung der Lagerungs-Verhältnisse, besonders in Deutschland - Schmidt, F. A. (Krais & Hoffmann, 1855)

Petri Artedi ... Ichthyologia sive opera omnia de piscibus, scilicet: Bibliotheca ichthyologica. Philosophia ichthyologica. Genera piscium. Synonymia specierum. Descriptiones specierum. Omnia in hoc genere perfectiora, quam antea ulla - Linné, Carl von, 1707 -1778 (apud Conradum Wishoff, 1738)

Petri Artedi ... Ichthyologia: sive, opera omnia de piscibus, scilicet: Bibliotheca ichthyologica. Philosophia ichthyologica. Genera piscium. Synonymia specierum. Descriptiones specierum. Omnia in hoc genere perfectiora, quam antea ulla - Artedi, Peter, 1705 -1735 (Apud Conradum Wishoff, 1738)

Petri Artedi renovati pars I. et II. [III-V] : i.e. bibliotheca et philosophia ichthyologica - Linné, Carl von, 1707 -1778 (Impensis A.F. Röse, 1792)

Petrifactions and their teachings, or, A hand-book to the gallery of organic remains of the British Museum - British Museum (Natural History). Department of Zoology. (H.G. Bohn, 1851)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1908)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1910)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1912)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1906)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1919)

Philosophia vetus et nova : ad usum scholae accommodata, in Regia Burgundia olim pertractata - Du Hamel, Jean-Baptiste, 1624 -1706 (Apud Stephanum Michallet via Jacobea, ad Insigne S. Pauli, 1684)

Philosophiae natvralis sive Physicae dogmaticae tomvs I[-IV] continens ... continvationem systematis philosophici Christiani L.B. de Wolff - Hanov, M. C. (Michael Christoph), 1695 -1773 (Prostat in officina libraria rengeriana, 1762)

The Philosophical magazine : comprehending the various branches of science, the liberal and fine arts, geology, agriculture, manufactures and commerce (Richard Taylor and Co, 1803)

Philosophical transactions of the Royal Society of London - Royal Society (Great Britain) (Royal Society of London, 1814)

Philosophical transactions of the Royal Society of London - Royal Society (Great Britain) (Royal Society of London, 1836)

The philosophy of zoology, or, A general view of the structure, functions, and classification of animals - Fleming, John, 1785 -1857 (Hurst, Robinson & Co, 1822)

The philosophy of zoology; or, A general view of the structure, functions, and classification of animals - Fleming, John, 1785 -1857 (A. Constable, 1822)

The phylogenetic position of Oreopithecus and its significance in the origin of the Hominoidea - Sarmiento, Esteban E. (American Museum of Natural History, 1987)

Physica sacra - Scheuchzer, Johann Jakob, 1672 -1733 (Christian Ulrich Wagner], 1731)

Physis - Sociedad Argentina de Ciencias Naturales. (Asociación Argentina de Ciencias Naturales [etc.], 1915)

Physis - Sociedad Argentina de Ciencias Naturales. (Asociación Argentina de Ciencias Naturales [etc.], 1918)