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)

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

Occasional papers - Texas Tech University. Museum, (The Museum, 1982)

Occasional papers - Texas Tech University. Museum, (The Museum, 1991)

Occasional papers - Texas Tech University. Museum, (The Museum, 1992)

Occasional papers - Texas Tech University. Museum, (The Museum, 2001)

Occasional papers - Texas Tech University. Museum, (The Museum, 2003)

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)

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

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.], 1890)

Öfversigt af Finska vetenskaps-societetens förhandlingar - Suomen Tiedeseura (s.n.], 1918)

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, 1898)

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)

Om rätta tydningen af sido-utskotten på rygg- och ländkotorna hos menniskan och däggdjuren - Retzius, A. (Anders), 1796 -1860 (Norstedt, 1850)

Om slägtet Sorex, med några nya arters beskrifning - Sundevall, Carl J., 1801 -1875 (Kungliga Vetenskapsakademien, 1842)

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 archetype and homologies of the vertebrate skeleton - Owen, Richard, 1804 -1892 (John Van Voorst, 1848)

On the classification and geographical distribution of the Mammalia, being a lecture on Sir Robert Reade's foundation, delivered before the University of Cambridge ... May 10, 1859. To which is added an appendix "On the gorilla," and "On the extinction and transmutation of species." - Owen, Richard, 1804 -1892 (J. W. Parker and son, 1859)

On the history and natural arrangement of insects - Shuckard, William Edward, 1802 -1868 (Printed for Longman, Brown, Green & Longman's Paternoster Row, 1840)

On the history and natural arrangement of insects - Shuckard, William Edward, 1802 -1868 (Printed for Longman, Orme, Brown, Green, & Longmans [etc.], 1840)

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

On the power, wisdom and goodness of God, as manifested in the creation of animals, and in their history, habits and instincts - Kirby, William, 1759 -1850 (Carey, Lea & Blanchard, 1836)

On the structure and development of the skull in the mammalia - Parker, William Kitchen William Kitchen Parker 1823 -1890 (Royal Society of London, 1874)

The ontogeny and phylogeny of the sternum - Hanson, Frank Blair, ([publisher not identified], 1919)

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 orders of mammals - Gregory, William K. (William King), 1876 -1970 (The Trustees, 1910)

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

Ornithologia Svecica - Nilsson, Sven, 1787 -1883 (Apud J.H. Schubothium, 1817)

[Ornithological papers] - Seebohm, Henry, 1832 -1895 (1876)

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)

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)