APA

Beck C. B., . (1976). Origin and early evolution of angiosperms. New York: Columbia University.

Chicago

Beck Charles B, . 1976. Origin and early evolution of angiosperms. New York: Columbia University.

Harvard

Beck C. B., . (1976). Origin and early evolution of angiosperms. New York: Columbia University.

MLA

Beck Charles B, . Origin and early evolution of angiosperms. New York: Columbia University. 1976.