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)

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

The Oregon naturalist (Naturalist Pub. Co, 1896)

The origin of species - Darwin, Charles, 1809 -1882 (Books, Inc, 1900)

The origin of species - Darwin, Charles, 1809 -1882 (Literary Classics, 1900)

The origin of species - Darwin, Charles, 1809 -1882 (P.F. Collier, 1909)

The origin of species by means of natural selecti : or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (1904)

The origin of species by means of natural selection, or, the preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (John Murray, 1872)

The origin of species : by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton & Co, 1889)

The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (John Murray, 1880)

The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (J. Murray, 1888)

The origin of species by means of natural selection; or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (J. Murray, 1886)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (A.L. Burt, 1899)

The origin of species by means of natural selection : or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (Merrill and Baker, 1900)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (A.L. Burt, 1894)

The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (J. Murray, 1902)

The origin of species by means of natural selection; or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Company, 1909)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton, 1899)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Company, 1917)

The origin of species by means of natural selection; or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Company, 1889)

The origin of species by means of natural selection; or, the preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and company, 1915)

The origin of species by means of natural selection : or The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (Hurst, 1872)

Origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (P. F. Collier, 1902)

Origin of species by means of natural selection, or the preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (P. F. Collier, 1905)

Origin of species - Darwin, Charles, 1809 -1882 (H.M. Caldwell Co, 1900)

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 species by means of natural selection - Darwin, Charles, 1809 -1882 (J. Murray, 1910)

Les origines animales de l'homme; éclairées par la physiologie et l'anantome comparatives - Durand, Joseph Pierre, 1826 -1900 (G. Baillière, 1871)

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

Ornithological dictionary of British birds - Rennie, James, 1787 -1867 (Hurst, Chance, 1831)

Ornithological dictionary of British birds - Rennie, James, 1787 -1867 (W. S. Orr & W. Smith, 1833)

Ornithological journal and register - Mearns, Edgar Alexander, 1856 -1916 (1874)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1894)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1895)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1897)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1901)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1903)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1904)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1910)

Ornithologisches Jahrbuch (V. Tschusi, 1907)

Ornithology - Jardine, William, 1800 -1874 (W.H. Lizars, 1855)

Ostéographie, ou, Description iconographique comparée du squelette et du système dentaire des Mammifères récents et fossiles : pour servir de base à la zoologie et à la géologie - Blainville, H.-M. Ducrotay de (Henri-Marie Ducrotay), 1777 -1850 (J.B. Baillière et fils, 1839)

Osteologia degli orsi fossili del Veronese, con un saggio sopra le principale caverne del distretto di Tregagno - Massalongo, Abramo, 1824 -1860 (1851)

Die österreichischen Diatomaceen, nebst Anschluss einiger neuen Arten von andern Lokalitäten und einer kritischen Uebersicht der bisher bekannten Gattungen und Arten - Grunow, A. (Albert), 1826 -1914 (1862)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1896)