Observationes entomologicae, continentes novorum quae condidit generum characteres, et nuper detectarum specierum descriptiones - Weber, Friedrich, 1781 -1823 (impensis Bibliopolii Academici Novi, 1801)

Observations on the gestation of some sharks and rays - Alcock, A. (Alfred), 1859 -1933 (Asiatic Society, 1891)

Occasional papers - San Diego Society of Natural History. (San Diego Society of Natural History, 1937)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1869)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1915)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1901)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1953)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1977)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2010)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1989)

Öfversigt af Finska vetenskaps-societetens förhandlingar - Suomen Tiedeseura (s.n.], 1905)

Öfversigt af Finska vetenskaps-societetens förhandlingar - Suomen Tiedeseura (s.n.], 1912)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1852)

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

On the Coleoptera known to occur in Indiana - Blatchley, W. S. (Willis Stanley), 1859 -1940 (W.B. Burford, contractor for state printing, 1910)

On the Coleoptera of the Island of Montreal - Ritchie, A. S. (s.n)

On the control of timber insects, of the hemileuca moth and the pear thrips - Reinlein, Fred, 1866 - (1915)

On the habits and instincts of animals - Swainson, William, 1789 -1855 (Printed for Longman, Orme, Brown, Green, & Longmans, 1840)

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 variation of species - Wollaston, Thomas Vernon, 1822 -1878 (John Van Voorst, 1856)

On the variation of species, with especial reference to the insecta followed by an inquiry into the nature of genera - Wollaston, Thomas Vernon, 1822 -1878 (J. Van Voorst, 1856)

On the variation of species : with especial reference to the Insecta : followed by an inquiry into the nature of genera - Wollaston, Thomas Vernon, 1822 -1878 (J. Van Voorst, 1856)

One hundred twenty-first annual report of the New York State Museum and Science service (University of the State of New York, State Education Dept, 1960)

Opuscula entomologica - Thomson, C. G. (Carl Gustav), 1824 -1899 (1875)

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

Orchard and farm (Calkins Newspaper Syndicate, 1898)

The orders, sub-orders and genera of insects - Couper, William, 1886 (s.n, 1864)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1899)

Ornithologische Monatsschrift - Deutscher Verein zum Schutze der Vogelwelt. (Kommissions-Verlag der Creutschen Verlagsbuchhandlung, 1905)

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

Ornithologisches Jahrbuch (V. Tschusi, 1901)

The Orthoptera of Indiana : an illustrated descriptive catalogue of the species known to occur in the state, with bibliography, synonymy and descriptions of new species - Blatchley, W. S. (Willis Stanley), 1859 -1940 ([Indiana Dept. of Geology and Natural Resources, 1903)

Orthoptera of northeastern America : with especial reference to the faunas of Indiana and Florida - Blatchley, W. S. (Willis Stanley), 1859 -1940 (Nature Pub. Co., 1920, 1920)

Orthoptera of northeastern America, with especial reference to the faunas of Indiana and Florida - Blatchley, W. S. (Willis Stanley), 1859 -1940 (The Nature Publishing Company, 1920)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1893)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1892)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1911)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1914)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1913)

Our common insects. A popular account of the insects of our fields, forests, gardens and houses - Packard, A. S. (Alpheus Spring), 1839 -1905 (Naturalists' Agency, 1873)

Our common insects A popular account of the insects of our fields, forests, gardens, and houses - Packard, A. S. (Alpheus Spring), 1839 -1905 (Estes and Lauriat, 1873)

Our forests : what they are and what they mean to us - Heisley, Marie Foote, 1888 - (U.S. Dept. of Agriculture, 1933)

Our forests : what they are and what they mean to us - Heisley, Marie Foote, 1888 - (U.S. Govt. Print. Off, 1940)

Our insect friends and foes - Duncan, F. Martin (Francis Martin), 1873 -1961 (Methuen, 1911)

The out-door world, or, Young collector's handbook - Furneaux, William S. (Longmans, Green, 1893)

Outline descriptions of British Coleoptera - Blackburn, Thomas, 1844 -1912 (Perthshire Society of Natural Science, 1875)

Outlines of entomology - Murtfeldt, Mary Esther, 1848 -1913 (Tribune Printing Company, State Printers and Binders, 1891)

Outlines of entomology, published in connection with the author's annual reports upon injurious insects Part first. Including the order of coleoptera - LeBaron, William. (State Journal Steam Print, 1874)

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, 1806)

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)

Palaeontology - Palaeontological Association (Palaeontological Association, 1959)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1892)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1907)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1914)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1918)

Pamphlets on forest protection (1900)

Pamphlets on forestry in Maine (1900)

Pamphlets on forestry in Ohio (1900)

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

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1943)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1954)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1956)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1961)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1979)

Papers and proceedings of the Royal Society of Tasmania - Royal Society of Tasmania. (The Society, 1886)

Papers and proceedings of the Royal Society of Tasmania - Royal Society of Tasmania. (The Society, 1903)

Papers and proceedings of the Royal Society of Van Diemen's Land - Royal Society of Tasmania. (Royal Society of Van Diemen's Land, 1855)

Papilio - Edwards, Henry, 1827 -1891 (New York Entomological Club, 1882)

Parasites and predators of the Mexican bean beetle in the United States - Howard, Neale F. (Neale Frederick), 1890 - (U.S. Dept. of Agriculture, 1936)

Parasites of the gypsy and brown-tail moths introduced into Massachusetts - Massachusetts. State forester. (Wright and Potter printing co., state printers, 1910)

Parasitology - British Society for Parasitology. (Cambridge University Press, 1914)

Parasitology (Cambridge University Press, 1918)

The Pennsylvania farm journal (A.M. Spangler, 1851)

Personality of insects - Dixon, Royal, 1885 -1962 (Clark, 1924)

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

Petites nouvelles entomologiques (E. Deyrolle, 1869)

Die Pflanzenwelt Deutschlands; Lehrbuch der Formations- biologie. Eine Darstellung der Lebensgeschichte der wildwachsenden Pflanzenvereine und der Kulturflächen - Graebner, Paul, 1871 -1933 (Quelle & Meyer, 1909)

Phegea - Vlaamse Vereniging voor Entomologie. (Vlaamse Vereniging voor Entomologie, 1981)

Phegea - Vlaamse Vereniging voor Entomologie. (Vlaamse Vereniging voor Entomologie, 1984)

Phegea - Vlaamse Vereniging voor Entomologie. (Vlaamse Vereniging voor Entomologie, 1985)

Phegea - Vlaamse Vereniging voor Entomologie. (Vlaamse Vereniging voor Entomologie, 2006)

The philosophy of zoology, or, A general view of the structure, functions, and classification of animals - Fleming, John, 1785 -1857 (Hurst, Robinson & Co, 1822)