APA

Simpson G. G., . (1961). Principles of animal taxonomy. New York: Columbia University Press.

Chicago

Simpson George Gaylord, . 1961. Principles of animal taxonomy. New York: Columbia University Press.

Harvard

Simpson G. G., . (1961). Principles of animal taxonomy. New York: Columbia University Press.

MLA

Simpson George Gaylord, . Principles of animal taxonomy. New York: Columbia University Press. 1961.