Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1882)

Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1911)

Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1916)

Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1918)

Obras completas y correspondencia científica - Ameghino, Florentino, 1853 -1911 (Taller de Impresiones Oficiales, 1921)

Observations on bats from Trinidad, with a checklist of species occuring on the island - Carter, Catherine H. (Museum, Texas Tech University, 1981)

Observations on bats of Córdoba and La Pampa provinces, Argentina - Tiranti Paz, Sergio I. (Museum of Texas Tech University, 1998)

Observations on the biology of some Rhodesian bats : including a key to the Chiroptera of Rhodesia - Royal Ontario Museum. (Royal Ontario Museum, 1975)

Occasional papers - Texas Tech University. Museum, (The Museum, 1972)

Occasional papers - Texas Tech University. Museum, (The Museum, 1974)

Occasional papers - Texas Tech University. Museum, (The Museum, 1976)

Occasional papers - Texas Tech University. Museum, (The Museum, 1978)

Occasional papers - Texas Tech University. Museum, (The Museum, 1979)

Occasional papers - Texas Tech University. Museum, (The Museum, 1980)

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

Occasional papers - Texas Tech University. Museum, (The Museum, 1983)

Occasional papers - Texas Tech University. Museum, (The Museum, 1984)

Occasional papers - Texas Tech University. Museum, (The Museum, 1985)

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

Occasional papers - Texas Tech University. Museum, (The Museum, 1987)

Occasional papers - Texas Tech University. Museum, (The Museum, 1988)

Occasional papers - Texas Tech University. Museum, (The Museum, 1989)

Occasional papers - Texas Tech University. Museum, (The Museum, 1991)

Occasional papers - Texas Tech University. Museum, (The Museum, 1992)

Occasional papers - Texas Tech University. Museum, (The Museum, 2001)

Occasional papers - Texas Tech University. Museum, (The Museum, 2002)

Occasional papers - Texas Tech University. Museum, (The Museum, 2003)

Occasional papers - Texas Tech University. Museum, (The Museum, 2009)

Occasional papers - Texas Tech University. Museum, (The Museum, 2011)

Occasional papers - Texas Tech University. Museum, (The Museum, 2019)

Occasional papers - Texas Tech University. Museum, (The Museum, 2020)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1904)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1986)

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

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2013)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1971)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1972)