APA
(1931). Biological Abstracts Nos (1 to 7). : Union of American Biological Societies U.S.A.
Chicago
1931. Biological Abstracts Nos (1 to 7). : Union of American Biological Societies U.S.A.
Harvard
(1931). Biological Abstracts Nos (1 to 7). : Union of American Biological Societies U.S.A.
MLA
Biological Abstracts Nos (1 to 7). : Union of American Biological Societies U.S.A. 1931.