De nuttige planten van Nederlandsch-Indië, tevens synthetische catalogus der verzamelingen van het Museum voor Technische- en Handelsbotanie te Buitenzorg - Heyne, K. (Ruygrok, 1913)

Occasional papers - Texas Tech University. Museum, (The Museum, 1982)

Occasional papers - Texas Tech University. Museum, (The Museum, 1986)

Okens Lehrbuch der Naturgeschichte - Oken, Lorenz, 1779 -1851 (Bei Carl Heinrich Reclam, 1816)

On "retrogression" in the evolution of the Phocinae and phylogenetic affinities of the monk seals - Wyss, André R. (American Museum of Natural History, 1988)

On some Indian forest grasses and their oecology - Hole, R. S. (Superintendent Government Printing, India, 1911)

The onion (ICAR-Directorate of Knowledge Management in Agriculture, Indian Council of Agricultural Research, 2015)

The orders of mammals - Gregory, William K. (William King), 1876 -1970 (The Trustees, 1910)

Organic livestock farming - Indian Council of Agricultural Research. Directorate of Knowledge Management in Agriculture. (Directorate of Knowledge Management in Agriculture, Indian Council of Agricultural Research, 2013)

Orthoptera (Acridiidae) - Kirby, W. F. (William Forsell), 1844 -1912 (Taylor and Francis ; [etc., etc.], 1914)

Ostéographie, ou, Description iconographique comparée du squelette et du système dentaire des Mammifères récents et fossiles : pour servir de base à la zoologie et à la géologie - Blainville, H.-M. Ducrotay de (Henri-Marie Ducrotay), 1777 -1850 (J.B. Baillière et fils, 1839)

The oviposition response of insects - Richardson, Charles H. (Charles Howard), 1887 - (U.S. Dept. of Agriculture, 1925)

The oxygen requirement of plant roots in relation to soil aeration - Free, E. E. (Edward Elway), 1883 -1939 (1917)

Pacific science - University of Hawaii. (University Press of Hawaii, 1947)

The pagan tribes of Borneo; a description of their physical, moral intellectual condition, with some discussion of their ethnic relations - Haddon, Alfred C. (Alfred Cort), 1855 -1940 (Macmillan, 1912)

The pagan tribes of Borneo; a description of their physical, moral and intellectual condition, with some discussion of their ethnic relations - Haddon, Alfred C. (Alfred Cort), 1855 -1940 (Macmillan and co., limited, 1912)

Palaeontology - Palaeontological Association (Palaeontological Association, 1993)

The palms of British India and Ceylon - Blatter, Ethelbert, 1877 -1934 (H. Milford, 1926)

Pamietnik Zakadu genetycznego = Mémoires de l'Institut de génétique - Szkoa Gówna Gospodarstwa Wiejskiego w Warszawie. Zakad Genetyki. (B. Wierzbicki, 1921)

Pamphlets on silviculture (1899)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1930)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1937)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1992)

Papaya - Ram, Mansha. (Indian Council of Agricultural Research, 2009)

Papers and proceedings of the Royal Society of Tasmania - Royal Society of Tasmania. (The Society, 1913)

Papers and published notes : 1869 to 1876 - Goode, G. Brown (George Brown), 1851 -1896 (1869)

Parasitology - British Society for Parasitology. (Cambridge University Press, 1910)

Parasitology - British Society for Parasitology. (Cambridge University Press, 1911)

Parasitology - British Society for Parasitology. (Cambridge University Press, 1917)

Parasitology (Cambridge University Press, 1922)

The Peanut, the unpredictable legume; a symposium - Arant, F. S. (Frank Selman), 1904 - (National Fertilizer Association, 1912)

Die Perlmuscheln und ihre Perlen. Naturwissenschaftlich und geschichtlich mit Berücksichtigung der Perlengewässer Bayerns - Hessling, Theodor von, 1816 -1899 (W. Engelmann, 1859)

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

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1917)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1919)

Physical properties of Hawaii soils with special reference to the colloidal fraction - Richter, Charles, 1892 - ([U.S. G.P.O.], 1931)

The physiology of reproduction - Marshall, F. H. A. (Francis Hugh Adam), 1878 -1949 (Longmans, Green, and co, 1922)

The physiology of reproduction - Marshall, F. H. A. (Francis Hugh Adam), 1878 -1949 (Longmans, 1922)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1978)

Phytologia - Moldenke, Harold N. (Harold Norman), 1909 -1996 (H.A. Gleason and H.N. Moldenke, 1986)

The pink bollworm, with special reference to steps taken by the Department of Agriculture to prevent its establishment in the United States - Hunter, W. D. (Walter David), 1875 -1925 (U.S. Dept. of Agriculture, 1926)

The place of the rural economy in a university curriculum - Somerville, William, 1860 - (Clarendon Pr, 1907)

The plant disease reporter - United States. Bureau of Plant Industry. (Bureau of Plant Industry, U.S. Dept. of Agriculture, 1942)

Plant exploration report for safflower and miscellaneous oilseeds, Near East and Mediterranean countries : March-October 1958 - United States. Agricultural Research Service. Crops Research Division. (USDA, ARS, Crops Research Division, 1959)

Plant growth substances - University of Wisconsin. (University of Wisconsin Press, 1951)

Plant habits and habitats in the arid portions of South Australia - Cannon, William Austin, 1870 -1958 (Carnegie Institute, 1921)

Plant habits and habitats in the arid portions of South Australia - Cannon, William Austin, 1870 -1958 (Carnegie Institution of Washington, 1921)

Plant immigrants - United States. Office of Foreign Seed; Plant Introduction. (Office of Foreign Seed and Plant Introduction, 1916)

Plant immigrants - United States. Office of Foreign Seed; Plant Introduction. (Office of Foreign Seed and Plant Introduction, 1917)

Plant immigrants - United States. Office of Foreign Seed; Plant Introduction. (Office of Foreign Seed and Plant Introduction, 1920)

Plant indicators: the relation of plant communities to process and practice - Clements, Frederic E. (Frederic Edward), 1874 -1945 (Carnegie Institution of Washington, 1920)

Plant inventory - United States. Agricultural Research Service. (Northeastern Region, Agricultural Research Center-West, 1923)

Plant inventory - United States. Agricultural Research Service. (Northeastern Region, Agricultural Research Center-West, 1929)

Plant inventory - United States. Agricultural Research Service. (Northeastern Region, Agricultural Research Center-West, 1934)