Observations in natural history : with an introduction on habits of observing, as connected with the study of that science ; also a calendar of periodic phenomena in natural history ; with remarks on the importance of such registers - Jenyns, Leonard, 1800 -1893 (John van Voorst, 1846)

Observations sur les hyménoptères d'Europe de la famille des fouisseurs - Vanderlinden, Pierre Léonard, 1797 -1831 (M. Hayez, 1829)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1875)

Occasional papers of the Natural History Society of Wisconsin - Peckham, Elizabeth G. (Elizabeth Gifford), 1854 -1940 (The Society, 1889)

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 Finska vetenskaps-societetens förhandlingar - Suomen Tiedeseura (s.n.], 1857)

Okens Lehrbuch der Naturgeschichte - Oken, Lorenz, 1779 -1851 (Bei Carl Heinrich Reclam, 1813)

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

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 instincts and habits of the solitary wasps - Peckham, Elizabeth G. (Elizabeth Gifford), 1854 -1940 (Published by the state, 1898)

On the origin of species - Darwin, Charles, 1809 -1882 (D. Appleton and Co, 1871)

On the origin of species - Darwin, Charles, 1809 -1882 (Appleton, 1904)

On the origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (Henry Frowde, 1907)

On 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 and Co, 1860)

On 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, Albemarle Street, 1859)

On 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, 1860)

On 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, 1859)

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

On the senses, instincts, and intelligence of animals, with special reference to insects - Lubbock, John, Sir, 1834 -1913 (K. Paul, Trench, 1889)

On the senses, instincts, and intelligence of animals : with special reference to insects - Lubbock, John, Sir, 1834 -1913 (Kegan Paul, Trench & Co, 1889)

On the senses, instincts, and intelligence of animals, with special reference to insects - Lubbock, John, Sir, 1834 -1913 (D. Appleton and Company, 1888)

On the senses, instincts, and intelligence of animals : with special reference to insects - Lubbock, John, Sir, 1834 -1913 (Kegan Paul, Trench, 1888)

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)

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, 1943)

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, 1946)