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)

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

Perfection seeds, bulbs, plants and garden requisites for 1921 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (William M. Hunt & Company, 1921)

Perfection seeds, bulbs, plants and garden requisites for 1922 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (William M. Hunt & Co., Inc, 1922)

Perfection seeds, bulbs, plants for 1920 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (William M. Hunt and Co, 1920)

Die periodischen Bewegungen der Blattorgane - Pfeffer, W. (Wilhelm), 1845 -1920 (Verlag von W. Engelmann, 1875)

Permanent and temporary pastures - Sutton, Martin John, 1850 -1913 (Simpkin, Marshall, Hamilton, Kent, 1911)

Permanent and temporary pastures - Sutton, Martin John, 1850 -1913 (Hamilton, Adams & Co, 1888)

Permanent and temporary pastures - Sutton, Martin John, 1850 -1913 (Simpkin, Marshall, Hamilton, Kent & Co, 1891)

Permanent and temporary pastures - Sutton, Martin John, 1850 -1913 (Simpkin, Marshall, Hamilton, Kent & Co, 1908)

Permanent and temporary pastures - Sutton, Martin John, 1850 -1913 (Simpkin, Marshall, Hamilton, Kent & Co., limited, 1911)

Permanent and temporary pastures, with descriptions and coloured illustrations of leading natural grasses and clovers - Sutton, Martin John, 1850 -1913 (Hamilton, Adams, 1887)

Permanent sample plot (psp) field procedures manual - Alberta. Alberta Sustainable Resource Development. (Alberta Sustainable Resource Development, Public Lands and Forests Division, Forest Management Branch, 2005)

Perry's seeds, bulbs, plants, 1946 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1946)

Perry's seeds, bulbs, plants, poultry supplies & sundries, 1943 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1943)

Perry's seeds, bulbs, plants, poultry supplies & sundries, 1944 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1944)

Perry's seeds, bulbs, plants, poultry supplies and sundries, 1942 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1942)

Perry's seeds, bulbs, plants, poultry supplies and sundries, 1945 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1945)

Perry's seeds, bulbs, plants, poultry supplies and sundries, 1941 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1941)

Perry Seed Company, 1929 : successors to Fiske Seed Co - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1929)

Perry Seed Company, 1931 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1931)

Perry Seed Company, 1932 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1932)

Perry Seed Company, successors to Fiske Seed Company : 1930 [catalog] - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Perry Seed Company, 1930)

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

Pests not known to occur in the United States or of limited distribution. no.51, Cabbage thrips - United States. Animal; Plant Health Inspection Service. Plant Protection; Quarantine Programs. (United States Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine, 1984)

Petite flore de la Mayenne - Léveillé, H. (Hector), 1863 -1918 (Goupil, 1895)

P.F. Cürie's Anleitung, die im mittleren und nördlichen Deutschland wildwachsenden und angebauten Pflanzen auf eine leichte und sichere Weise durch eigene Untersuchung zu bestimmen - Cürie, P. F. (C.G. Zobel, 1856)

Pflanzen-Atlas nach dem Linné'schen System - Hoffmann, Carl, 1802 -1883 (Jul. Hoffmann, 1881)

Pflanzen-teratologie systematisch geordnet - Penzig, O. (Ottone), 1856 -1929 (A. Ciminago, 1894)

Die Pflanzen und Raupen Deutschlands : Versuch einer lepidopterologischen Botanik - Wilde, O. (E.S. Mittler, 1860)

Pflanzenbiologische Studien - Lundström, Axel Nikolaus, 1847 -1905 (Druck der Akademischen Buchdruckerei, Edv. Berling, 1884)

Die Pflanzendecke der Erde : populäre Darstellung der Pflanzengeographie für gebildete Naturfreunde - Rudolph, Ludwig, 1813 -1896 (Nicolaische Verlagsbuchhandlung, 1859)

Die Pflanzendecke Österreich-Ungarns. Auf Grund fremder und eigener Forschungen geschildert - Hayek, August von, 1871 -1928 (F. Deuticke, 1914)

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)

Pflanzenmikrochemie : ein Hilfsbuch beim mikrochemischen Studium pflanzlicher Objekte - Tunmann, Otto, 1867 -1919 (Gebrüder Borntraeger, 1913)

Pflanzenphysiologie als Theorie der Gärtnerei. Für Botaniker, Gärtner, Landwirte, Forstleute und Pflanzenfreunde - Molisch, Hans, 1856 -1937 (G. Fischer, 1922)

Pflanzenphysiologie; ein Handbuch der Lehre vom Stoffwechsels und Kraftwechsels in der Pflanze - Pfeffer, W. (Wilhelm), 1845 -1920 (W. Engelmann, 1897)