Potter's cyclopaedia of botanical drugs and preparations - Holmes, E. M. (Edward Morell), 1843 -1930 (Potter & Clarke, 1915)

Potter's cyclopedia of botanical drugs and preparations - Wren, R. C. (Richard Cranfield), 1864 -1931 (Potter & Clarke, 1900)

Practical botany - Bergen, Joseph Y. (Joseph Young), 1851 -1917 (Ginn and company, 1911)

Practical botany - Bergen, Joseph Y. (Joseph Young), 1851 -1917 (Ginn, 1911)

Practical farming and gardening; or, Money saving methods in farming, gardening, fruit growing, also horse, cattle, sheep, hog and poultry raising ... - MacGerald, Willis, (The S.A. Mullikin Company, 1914)

Practical veterinary pharmacology and therapeutics - Milks, Howard Jay, 1879 -1954 (The Macmillan company, 1917)

Practical veterinary pharmacology and therapeutics - Milks, Howard Jay, 1879 -1954 (The Macmillan Company, 1917)

Preliminary catalogue of plants poisonous to stock - Chesnut, V. K. (Victor King), 1867 -1938 (1898)

A preliminary catalogue of the flora of New Jersey - Britton, Nathaniel Lord, 1859 -1934 (Office of the Survey, 1881)

... A preliminary catalogue of the flora of New Jersey - Britton, Nathaniel Lord, 1859 -1934 (Office of the survey, 1881)

Preliminary catalogue of the flora of West Virginia - Millspaugh, Charles Frederick, 1854 -1923 (1892)

A preliminary check list of the cryptogams and phanerogams in the vicinity of Saint Louis, Missouri - Engelmann Botanical Club. Check List Committee. (The Club, 1911)

Preliminary host index to fungi of Mount Shasta, California - United States. Division of Mycology; Disease Survey. (Division of Mycology and Disease Survey, Bureau of Plant Industry, United States Department of Agriculture, 1940)

A preliminary list of Maine fungi - Ricker, Percy Leroy, 1878 -1973 (1902)

A preliminary list of the parasitic fungi of Idaho - United States. Division of Mycology; Disease Survey. (Division of Mycology and Disease Survey, Bureau of Plant Industry, United States Department of Agriculture, 1936)

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The principles of botany, and of vegetable physiology - Willdenow, Karl Ludwig, 1765 -1812 (Printed at the University Press, for William Blackwood, 1805)

The principles of botany, and of vegetable physiology / translated from the German of D.C. Willdenow - Willdenow, Karl Ludwig, 1765 -1812 (Blackwood, 1811)

Principles of botany - Bergen, Joseph Y. (Joseph Young), 1851 -1917 (Ginn & company, 1906)

Principles of botany - Bergen, Joseph Y. (Joseph Young), 1851 -1917 (Ginn & Company, 1906)

Principles of plant culture; an elementary treatise designed as a text-book for beginners in agriculture and horticulture - Goff, E. S. (Emmett Stull), 1852 -1902 (The Author, 1899)

Principles of plant culture; an elementary treatise designed as a text-book for beginners in agriculture and horticulture - Goff, E. S. (Emmett Stull), 1852 -1902 (University Co-operative Co, 1912)

Principles of plant culture; an elementary treatise designed as a text-book for beginners in agriculture and horticulture - Goff, E. S. (Emmett Stull), 1852 -1902 (The author, 1897)

Principles of plant culture; an elementary treatise designed as a text-book for beginners in agriculture and horticulture - Goff, E. S. (Emmett Stull), 1852 -1902 (1897)

Principles of plant culture; an elementary treatise designed as a text-book for beginners in agriculture and horticulture - Goff, E. S. (Emmett Stull), 1852 -1902 (University Co-operative Co, 1906)

Principles of plant pathology - Owens, Charles Elmer, 1877 - (Wiley, 1928)

Principles of plant physiology - Raber, Oran, 1893 -1940 (The Macmillan Co, 1938)

The principles of plant-teratology - Worsdell, Wilson Crosfield (The Ray Society, 1915)

The principles of plant-teratology - Worsdell, Wilson Crosfield (The Ray Society, 1916)

The principles of vegetable-gardening - Bailey, L. H. (Liberty Hyde), 1858 -1954 (The Macmillan company, 1921)

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Proceedings and transactions of the Natural History Society of Glasgow - Natural History Society of Glasgow. (The Society, 1892)

The Proceedings and transactions of the Nova Scotian Institute of Science - Nova Scotian Institute of Science. (Nova Scotian Institute of Science, 1906)

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

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, 1882)

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 Academy of Arts and Sciences - American Academy of Arts; Sciences. (Metcalf and Co, 1882)

Proceedings of the American Philosophical Society held at Philadelphia for promoting useful knowledge - American Philosophical Society. (American Philosophical Society, 1918)

Proceedings of the Bath Natural History and Antiquarian Field Club - Bath Natural History; Antiquarian Field Club. (1874)

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

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1868)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1890)

Proceedings of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1903)