Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1921)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1923)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1924)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1925)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1915)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1963)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1970)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1977)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2010)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1978)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1993)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1910)

Öfversigt af Finska vetenskaps-societetens förhandlingar - Suomen Tiedeseura (s.n.], 1916)

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

The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1912)

The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1918)

The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1919)

The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1920)

The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1921)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1907)

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, 1909)

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

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1912)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1913)

L'Oiseau et la Revue francaise d'ornithologie - Société ornithologique de France. (Société ornithologique de France, 1978)

On the oxen-born bees of the ancients (bugonia) and their relation to Eristalis tenax, a two-winged insect - Osten-Sacken, C. R. (Carl Robert), 1828 -1906 (J. Hoerning, 1894)

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

The ontogeny of insects; [papers] - Ceskoslovenská akademie ved. Sekce biologicka-lékarská. (Academic Press, 1960)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1946)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1957)

The Orchadian - Australasian Native Orchid Society (The Society, 1967)

The Orchadian - Australasian Native Orchid Society (The Society, 1963)

Pacific science - University of Hawaii. (University Press of Hawaii, 1952)

Pacific science - University of Hawaii. (University Press of Hawaii, 1961)

Palaeontology - Palaeontological Association (Palaeontological Association, 1967)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1881)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1882)

Pamphlets on forest protection (1900)

Pamphlets on forestry in Maine (1900)