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, 1945)

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)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1873)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1874)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1884)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1896)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1897)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1894)

Opuscula Ichneumonologica : Fascicule 1-45 - Schmiedeknecht, Otto, 1847 -1936 ([s.n.], 1902)

Opuscula Ichneumonologica : Fascicule 1-45 - Schmiedeknecht, Otto, 1847 -1936 ([s.n.], 1904)

Opuscula Ichneumonologica : Fascicule 1-45 - Schmiedeknecht, Otto, 1847 -1936 ([s.n.], 1906)

Opuscula Ichneumonologica : Fascicule 1-45 - Schmiedeknecht, Otto, 1847 -1936 ([s.n.], 1908)

Opuscula Ichneumonologica : Fascicule 1-45 - Schmiedeknecht, Otto, 1847 -1936 ([s.n.], 1910)

Opuscules entomologiques - Mulsant, Martial Étienne, 1797 -1880 (L. Maison, 1853)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1908)

Our native orchids; a series of drawings from nature of all the species found in the northeastern United States - Gibson, W. Hamilton (William Hamilton), 1850 -1896 (Doubleday, Page & Co, 1905)

Overzicht der schadelijke en nuttige insecten van Java - Koningsberger, J. C. (Jacob Christiaan), 1867 -1951 (G. Kolff & co, 1908)

P.A. Latreille scientiarum et artium instituti Gallici ... Genera crustaceorum et insectorum : secundum ordinem naturalem in familias disposita, iconibus exemplisque plurimis explicata - Latreille, P. A. (Pierre André), 1762 -1833 (Apud Amand Knig, Bibliopolam, 1807)

P.A. Latreille scientiarum et artium instituti Gallici ... Genera crustaceorum et insectorum : secundum ordinem naturalem in familias disposita, iconibus exemplisque plurimis explicata - Latreille, P. A. (Pierre André), 1762 -1833 (Apud Amand Knig, Bibliopolam, 1809)

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

Pamphlets on forestry in Ohio (1900)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1958)

Papers on Diptera - Aldrich, John Merton, 1866 -1934 (Smithsonian Institution, 1913)

Papers on pollination - Darwin, Charles, 1809 -1882 (1861)

Pesticides documentation bulletin - National Agricultural Library (U.S.) (National Agricultural Library, U.S. Dept. of Agriculture, #c 1965-1969, 1965)

Petite faune entomologique du Canada et particulièrement de la province de Québec vol. II comprenant les orthoptères, les névroptères et les hyménoptères - Provancher, L. (Léon), 1820 -1892 (s.n.], 1883)

Die Pflanzenfeinde aus der Klasse der Insekten. Ein nach Pflanzenfamilien geordnetes Handbuch sämmtlicher auf den einheimischen Pflanzen bisher beobachteten Insekten zum Gebrauch für Entomologen, Insektensammler, Botaniker, Land- und Forstwirthe und Gartenfreunde - Kaltenbach, J. H. (Johann Heinrich), 1807 -1876 (J. Hoffmann, 1874)

Pflanzenphänologische Beobachtungen in Finland ... - Brotherus, V. F. (Viktor Ferdinand), 1849 -1929 (Druckerei der Finnischen Litteraturgesellschaft, 1874)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1922)

Pinacographia : illustrations of more than 1,000 species of north-west-European Icheumonide, sensu Linnaeano = Afbeeldingen van meer dan 1,000 soorten noord-west-Europeesche sluipwespen (ichneumones sensu Linnaeano) - Snellen van Vollenhoven, S. C. (Samuel Constant), 1816 -1880 (Martinus Nijhoff, 1880)

Pinacographia. Illustrations of more than 1,000 species of north-west-European Ichneumonide, sensu Linnaeano. Afbeeldingen van meer dan 1,000 soorten noord-west-europeesche sluipwespen (ichneumones sensu Linnaeano) - Snellen van Vollenhoven, S. C. (Samuel Constant), 1816 -1880 (M. Nijhoff, 1880)

The primaeval world of Switzerland - Heer, Oswald, 1809 -1883 (Longmans, Green, 1876)

Proceedings - Entomological Society of Canada (1863-1871) (Entomological Society of Ontario, 1895)

Proceedings and transactions of the Natural History Society of Glasgow - Natural History Society of Glasgow. (The Society, 1886)

Proceedings - Cambridge Philosophical Society Mathematical and physical sciences - Cambridge Philosophical Society. (Cambridge Philosophical Society [etc.], 1892)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1843)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1874)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1873)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1879)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1892)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1894)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1913)