A practical handbook of British birds - Witherby, H. F. (Harry Forbes), 1873 -1944 (Witherby, 1924)

Praktische Naturgeschichte der Vögel, für Gebildete aller Stände - Reichenbach, A. B. (Anton Benedikt), 1807 -1880 (1850)

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 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)

Primo resoconto dei risultati della inchiesta ornitologica in Italia ... - Giglioli, Enrico Hillyer, 1845 -1909 (Coi tipi dei successori Le Monnier, 1889)

Prírodopis prostonárodni : cili popsání zwírat, rostlin a nerostu : wedlé tríd a rádu jejich - Stanka, Wáclawa. (W kommissi u Kronbergra a Riwnáce, 1843)

Proceedings - Essex Institute. (1856)

Proceedings - Dorset Natural History; Archaeological Society.

Proceedings and transactions of the Liverpool Biological Society - Liverpool Biological Society. (The Society, 1894)

Proceedings and transactions of the Liverpool Biological Society - Liverpool Biological Society. (The Society, 1899)

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)

Proceedings and transactions of the Royal Society of Canada. Délibérations et mémoires de la Société royale du Canada - Royal Society of Canada. (Société royale du Canada, 1883)

Proceedings at the annual meeting of the Natural History Society of Montreal - Natural History Society of Montreal. (Mitchell & Wilson, 1881)

Proceedings - Dorset Natural History and Archaeological Society - Dorset Natural History; Archaeological Society. (1877)

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, 1859)

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, 1862)

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, 1864)

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, 1883)

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, 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, 1918)

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 Bath Natural History and Antiquarian Field Club - Bath Natural History; Antiquarian Field Club. (1882)

Proceedings of the Belfast Natural History and Philosophical Society - Belfast Natural History; Philosophical Society. (1874)

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, 1937)

Proceedings of the Biological Society of Washington - Smithsonian Institution (Biological Society of Washington, 1999)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1848)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1861)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1865)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1872)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1878)

Proceedings of the Bournemouth Natural Science Society - Bournemouth Natural Science Society (1928)

Proceedings of the Bournemouth Natural Science Society - Bournemouth Natural Science Society (1933)

Proceedings of the Bournemouth Natural Science Society - Bournemouth Natural Science Society (1934)

Proceedings of the Bournemouth Natural Science Society - Bournemouth Natural Science Society (1936)

Proceedings of the Bristol Naturalists' Society - Bristol Naturalists' Society (Bristol, England) (Bristol Naturalists' Society, 1935)

Proceedings of the Bristol Naturalists' Society - Bristol Naturalists' Society (Bristol, England) (Bristol Naturalists' Society, 1944)

Proceedings of the California Academy of Natural Sciences - California Academy of Natural Sciences (The Academy, 1863)

Proceedings of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1868)

Proceedings of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1889)

Proceedings of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1896)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1910)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1913)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1908)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1923)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1927)

Proceedings of the California Academy of Sciences, 4th series - California Academy of Sciences (California Academy of Sciences, 1935)