Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1914)

Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1915)

Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1916)

Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1917)

Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1918)

Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1920)

Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1921)

Obseruationes circa viuentia, quæ in rebus non viuentibus reperiuntur : Cum micrographia curiosa siue Rerum minutissimarum obseruationibus, quæ ope microscopij recognitæ ad viuum exprimuntur : his accesserunt aliquot animalium testaceorum icones non antea in lucem editæ : omnia curiosorum naturæ exploratorum vtilitati & iucunditati expressa & oblata - Buonanni, Filippo, 1638 -1725 (Typis Dominici Antonij Herculis, 1691)

Observations on llama remains from Colorado and Kansas - Cragin, Francis Whittemore, 1858 - (1892)

Occasional papers - Texas Tech University. Museum, (The Museum, 1978)

Occasional papers - Texas Tech University. Museum, (The Museum, 1979)

Occasional papers - Texas Tech University. Museum, (The Museum, 1988)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1979)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1978)

Occasional papers - Tulane University. Museum of Natural History. (The Museum, 1982)

Odontographie. Vergleichende Darstellung des Zahnsystemes der lebenden und fossilen Wirbelthiere - Giebel, C. (Christoph), 1820 -1881 (A. Abel, 1855)

Odontography : or a treatise on the comparative anatomy of the teeth, their physiological relations, mode of development and microscopic structure, in the vertebrate animals - Owen, Richard, 1804 -1892 (Hippolyte Bailliere, 1840)

Odontography; or, A treatise on the comparative anatomy of the teeth; their physiological relations, mode of development, and microscopic structure, in the vertebrate animals - Owen, Richard, 1804 -1892 (H. Baillière, 1840)

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

Oeuvres complètes de Buffon : avec des extraits de Daubenton, et la classification de Cuvier - Cuvier, Georges, baron, 1769 -1832 (Au Bureau des publications illustrées, 1849)

Oeuvres complètes de Buffon avec des extraits de Daubenton, et la classification de Cuvier : tome 1-9 - Cuvier, Georges, baron, 1769 -1832 (Deros & Cie, 1852)

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

Oeuvres complètes de M. le C.te de Buffon - Buffon, Georges Louis Leclerc, comte de, 1707 -1788 (De l'Imprimerie royale, 1774)

Oeuvres de Descartes - France. Ministère de l'Instruction publique (L. Cerf, 1897)

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, 1846)

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, 1869)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1872)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1873)

Ohrknorpel und äusseres ohr der Säugetiere; eine vergleichend-anatomische Untersuchung - Boas, J. E. V. (Johan Erik Vesti), 1855 -1935 ([Nielsen & Lydiche (A. Simmelkiær)], 1912)

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

Old bones : or, Notes for young naturalists, on vertbebrate animals, their fossil predecessors and allies - Symonds, W. S. 1818 -1887 (Robert Hardwicke, 1864)

The old English war-horse : or the great horse as it appears, at intervals, in contemporary coins and pictures during the centuries of its development into the shire-horse - Gilbey, Walter, Sir, 1831 -1914 (Vinton, 1888)

Omnium stirpium sciagraphia et icones : quibus plantarum et radicum tum in hortis cultarum, tum in vrbium fossis & muris, pratis, aruis, montibus, collibus, nemoralibus, fluviis, riguis & littoralibus, villis & pagis, spontè provenientium, nomina, figura, natura, natales, synonyma, vsus & virtutes, docentur : cum doctissimorum scriptorum circa eas consensu & dissensu - Chabrey, Dominique, 1610 -1669 (Sumptibus Samuelis de Tournes, 1678)

On agriculture, with a recension of the text and an English translation by Harrison Boyd Ash - Columella, Lucius Junius Moderatus. (Harvard University Press, 1941)

On farming : M. Terenti Varronis Rerum rusticarum libri tres - Storr-Best, Lloyd, (G. Bell, 1912)

On growth and form - Thompson, D'Arcy Wentworth, 1860 -1948 (University press, 1917)

On growth and form - Thompson, D'Arcy Wentworth, 1860 -1948 (University Press, 1945)

On mammalian descent the Hunterian Lectures for 1884 : being nine lectures delivered in the theatre of the Royal College of Surgeons during February, 1884 - Parker, William Kitchen William Kitchen Parker 1823 -1890 (C. Griffin, 1885)

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

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

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