APA (7th ed.) Citation

Ekman, P. (1973). Darwin and facial expression: A century of research in review. Academic Press.

Chicago Style (17th ed.) Citation

Ekman, Paul. Darwin and Facial Expression: A Century of Research in Review. New York: Academic Press, 1973.

MLA (9th ed.) Citation

Ekman, Paul. Darwin and Facial Expression: A Century of Research in Review. Academic Press, 1973.