A phylogeny of the thirty-three genera in the Empidonax assemblage of tyrant flycatchers - Lanyon, Wesley E. (American Museum of Natural History, 1986)

A phylogeny of the thirty-two genera in the Elaenia assemblage of tyrant flycatchers - Lanyon, Wesley E. (American Museum of Natural History, 1988)

Pocket guide to the common land birds of New England - Willcox, M. A. (Mary Alice), 1856 -1953 (Lee and Shepard, 1895)

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)

A pocket list of the birds of eastern Massachusetts, with especial reference to Essex County - Morse, Albert P. (Albert Pitts), 1863 -1936 (Peabody academy of science, 1912)

Point Lobos Reseerve; State Park, California - California. Division of Beaches; Parks. ([State Print. Off, 1954)

A popular handbook of the birds of Canada and the United States - Nuttall, Thomas, 1786 -1859 (Musson Book Co, 1903)

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, and Company, 1897)

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, 1887)

The Popular science monthly - Harry Houdini Collection (Library of Congress) (Popular Science Pub. Co., etc, 1906)

Postilla - Peabody Museum of Natural History. (Peabody Museum of Natural History, 1968)

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

Potential wildlife-highway interactions at select mile-markers along Montana Department of Transportation routes an ArcView GIS analysis - Irby, Lynn R. (Fish and Wildlife Management Program, Montana State University, 2001)

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 catalogue of the flowering plants and higher cryptogams growing without cultivation within thirty miles of Hanover, N.H., to which is appended a list of the vertebrates of the same region - Jesup, Henry G. (Henry Griswold), 1826 -1903 (N.A. McClary, 1882)

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 Jones Beach, Long Island, N.Y - Linnaean Society of New York (Linnaean Society of New York, 1935)

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)

A preliminary review of the birds of Nebraska : with synopses - Wolcott, Robert Henry, 1868 -1934 (Klopp & Bartlett Co, 1904)

Proceedings - Essex Institute. (1856)

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

The proceedings and transactions of the Nova Scotian Institute of Science, Halifax, Nova Scotia - Nova Scotian Institute of Science. (Printed for the Institute by W. McNab, 1895)

Proceedings and transactions of the Nova Scotian Institute of Natural Science - Nova Scotian Institute of Natural Science. (Nova Scotian Institute of Natural Science, 1886)

The Proceedings and transactions of the Nova Scotian Institute of Science - Nova Scotian Institute of Science. (Nova Scotian Institute of Science, 1915)

The Proceedings and transactions of the Nova Scotian Institute of Science - Nova Scotian Institute of Science. (Nova Scotian Institute of Science, 1918)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1859)

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, 1871)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1872)

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, 1892)

Proceedings of the Academy of Natural Sciences of Philadelphia - Academy of Natural Sciences of Philadelphia. (Academy of Natural Sciences of Philadelphia, 1893)

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, 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 American Philosophical Society held at Philadelphia for promoting useful knowledge - American Philosophical Society. (American Philosophical Society, 1909)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1885)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1882)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1904)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1903)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1906)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1911)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1922)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1935)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1937)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1940)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1947)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1965)