Pennsylvania bird life; a manual of the birds of Pennsylvania; treating especially of their food, from examinations of several thousand stomachs, made during all seasons of the year, with descriptions of the birds, their nests, eggs and habits - Warren, Benjamin Harry, 1858 -1926 (Penn'a., Pub by the author, 1892)

Penny Cyclopaedia of the Society for the Diffusion of Useful Knowledge - Society for the Diffusion of Useful Knowledge (Great Britain) (Charles Knight, 1833)

Per una classificazione elementare dei Passercei, Rampicanti e Trogoni, raccolta e ordinamento di alcuni caratteri - Cavazza, Filippo. (Tipografia di Paolo Neri, 1909)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1907)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1906)

The Philosophical magazine : or Annals of chemistry, mathematics, astronomy, natural history and general science (Richard Taylor and Co, 1827)

Pocket key of the birds of the northern United States, east of the Rocky Mountains - Apgar, A. C. (Austin Craig), 1838 -1908 (J.L. Murphy Pub. Co., Printers, 1893)

The popular encyclopedia; being a general dictionary of arts, sciences, literature, biography, history, and political economy, reprinted from the American edition of the "Conversations lexicon" ... with dissertations on the rise and progress of literature (Blackie, 1900)

A popular handbook of the birds of the United States and Canada - Nuttall, Thomas, 1786 -1859 (Little, Brown, 1903)

A popular handbook of the birds of the United States and Canada - Nuttall, Thomas, 1786 -1859 (Little, Brown, 1905)

A popular handbook of the birds of the United States and Canada - Nuttall, Thomas, 1786 -1859 (Little, Brown, 1921)

A popular handbook of the birds of the United States and Canada - Nuttall, Thomas, 1786 -1859 (Little, Brown, 1919)

A popular handbook of the ornithology of eastern North America - Nuttall, Thomas, 1786 -1859 (Little, Brown, 1891)

A popular Handbook of the Ornithology of Eastern North America - Nuttall, Thomas, 1786 -1859 (Truslove and Hanson, 1894)

A popular handbook of the ornithology of eastern North America - Nuttall, Thomas, 1786 -1859 (Little, Brown, and Company, 1896)

A popular handbook of the ornithology of the United States and Canada, based on Nuttall's Manual - Nuttall, Thomas, 1786 -1859 (Little, Brown, and Company, 1891)

The Popular science monthly - Harry Houdini Collection (Library of Congress) (Popular Science Pub. Co., etc, 1875)

Postilla - Peabody Museum of Natural History. (Peabody Museum of Natural History, 1982)

A preliminary catalog of the birds of Missouri - Widmann, Otto (Academy of Science of St. Louis, 1907)

A preliminary catalog of the birds of Missouri - Widmann, Otto (Academy of Sciences of St. Louis?, 1907)

A preliminary list of the birds found in Vermont - Perkins, George H. (George Henry), 1844 -1933 (Wynkoop Hallenbeck Crawford Co, 1901)

A preliminary list of the birds of Wayne County, Ohio - Oberholser, Harry C. (Harry Church), 1870 -1963 (Westbote Co., State Printers, 1896)

A preliminary report on the biology of Harding County, northwestern South Dakota - Visher, Stephen Sargent, 1887 -1967 (State Publishing Co, 1914)

Problems of genetics - Bateson, William, 1861 -1926 (Yale University Press, 1913)

Problems of genetics - Bateson, William, 1861 -1926 (Yale University Press, 1916)

Problems of genetics - Bateson, William, 1861 -1926 (Yale University Press; [etc., etc.], 1913)

Proceedings - Essex Institute. (1856)

The Proceedings and transactions of the Nova Scotian Institute of Science - Nova Scotian Institute of Science. (Nova Scotian Institute of Science, 1894)

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Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1846)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1848)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1850)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1852)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1854)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1856)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1860)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1861)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1863)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1865)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1866)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1868)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1869)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1871)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1875)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1877)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1883)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1886)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1889)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1890)

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, 1895)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1896)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1898)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1899)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1907)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1908)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1909)

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

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1841)

Proceedings of the ... annual meeting of the Florida State Horticultural Society - Florida State Horticultural Society. Meeting. (The Society, 1915)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1908)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1921)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1929)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1987)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1856)