The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1909)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1906)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1903)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1911)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1983)

On the taxonomic identity of Pteronotus davyi incae Smith, 1972 (Chiroptera: Mormoopidae) - Pacheco, Víctor (American Museum of Natural History, 2021)

Opuscula zoologica - Zoologische Staatssammlung München. (Zoologische Staatssammlung, 1971)

Oréades - Instituto de Ciências Biológicas da UFMG. Departamento de Botânica. (Departamento de Botânica, U.F.M.G, 1977)

Oréades - Instituto de Ciências Biológicas da UFMG. Departamento de Botânica. (Departamento de Botânica, U.F.M.G, 1981)

The organic constituents of higher plants: their chemistry and interrelationships - Robinson, Trevor. (Burgess Pub. Co, 1963)

The ornamental trees of Hawaii - Rock, Joseph F. (Joseph Francis), 1884 -1962 (1917)

Ornithological gazetteer of Brazil - Traylor, Melvin A. (Melvin Alvah), 1915 -2008 (Obtainable from Bird Dept., Museum of Comparative Zoology, Harvard University, 1991)

Ornithological science - Nihon Chogakkai (Ornithological Society of Japan, 2002)

Our native trees and how to identify them : a popular study of their habits and their peculiarities - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (C. Scribner's Sons, 1900)

Our native trees and how to identify them; a popular study of their habits and their peculiarities - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (Scribner, 1902)

Our South African flora = Ons Suid-Afrikaanse plantegroei - Compton, R. H. (Cape Times, 1900)

An outline of plant geography (The Macmillan company, 1926)

Oxford gardens, based upon Daubeny's Popular guide to the physick garden of Oxford: with notes on the gardens of the colleges and on the University park - Gunther, R. T. (Robert Theodore), 1869 -1940 (Parker & son; [etc., etc.], 1912)

Oxford gardens. Based upon Daubeny's Popular guide to the physick garden of Oxford : with notes on the gardens of the colleges and on the University Park - Gunther, R. T. (Robert Theodore), 1869 -1940 (Parker, 1912)

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

Pacific science - University of Hawaii. (University Press of Hawaii, 1949)

Pacific science - University of Hawaii. (University Press of Hawaii, 1950)

Pacific science - University of Hawaii. (University Press of Hawaii, 1951)

Pacific science - University of Hawaii. (University Press of Hawaii, 1953)

Pacific science - University of Hawaii. (University Press of Hawaii, 1959)

Pacific science - University of Hawaii. (University Press of Hawaii, 1960)

Pacific science - University of Hawaii. (University Press of Hawaii, 1962)

Pacific science - University of Hawaii. (University Press of Hawaii, 1967)

Pacific science - University of Hawaii. (University Press of Hawaii, 1968)

Palaeontographica Americana - Paleontological Research Institution (Ithaca, N.Y.) (Paleontological Research Institution, 1994)

Palaeontology - Palaeontological Association (Palaeontological Association, 1960)

Paleobotany and biogeography : a festschrift for Alan Graham in his 80th year - Raven, Peter H (Missouri Botanical Garden, 2014)

Paleobotany, paleoecology, and evolution - Niklas, Karl J (Praeger, 1900)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1896)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1917)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1918)

[Pamphlets on agriculture in Guam] (s.n, 1905)

Pamphlets on forestry in Minnesota (1900)

Pamphlets on forestry in Texas (1900)

Pamphlets on silviculture (1899)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1990)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1995)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 2002)

Part I. The living flora of West Virginia - Millspaugh, Charles Frederick, 1854 -1923 (Wheeling news litho. co, 1913)

Parthenogenesis und Apogamie im Pflanzenreiche - Winkler, Hans, 1877 - (G. Fischer, 1908)

Pathological plant anatomy - Küster, E. (Ernst), 1874 -1953 (1913)

Pathologische Pflanzenanatomie. In ihren Grundzügen - Küster, E. (Ernst), 1874 -1953 (G. Fischer, 1916)

Pennsylvania-German names of trees - Mell, Clayton D. (Clayton Dissinger), 1875 -1945 (Rev. P.C. Croll, 1910)

Perú: Cordillera Escalera-Loreto - Stotz, Douglas F. (Douglas Forrester), 1956 - (The Field Museum, Science and Education, 2014)

Peru : Ere-Campuya-Algodón - Field Museum of Natural History. (The Field Museum, Science and Education, 2013)

Peru : Maijuna - Alverson, William Surprison (Field Museum, Environment, Culture and Conservation, 2010)

Perú : Cerros de Kampankis - Stotz, Douglas F. (Douglas Forrester), 1956 - (The Field Museum, Environment, Culture, and Conservation, 2012)

Perú, Medio Putumayo-Algodón - Stotz, Douglas F. (Douglas Forrester), 1956 - (Field Museum of Natural History, 2016)

Perú : Nanay-Mazán-Arabela - Alverson, William Surprison (Field Museum, Environmental and Conservation Programs, 2007)

Perú : Tapiche-Blanco - Field Museum of Natural History. (The Field Museum, 2015)

Perú : Yaguas-Cotuhé - Field Museum of Natural History. (Field Museum, Environment, Culture, and Conservation, 2011)

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

Peter S. Ashton Sarawak fieldwork papers - Ashton, Peter S. (Peter Shaw), 1934 - (1963)