Cita APA (7th ed.)

Ekman, P., & Friesen, W. V. (1978). Facial action coding system. Investigator's guide: Paul Ekman ; Wallace V. Friesen. Consulting Psychologists Pr..

Cita Chicago (17th ed.)

Ekman, Paul, i Wallace V. Friesen. Facial Action Coding System. Investigator's Guide: Paul Ekman ; Wallace V. Friesen. Palo Alto, Calif.: Consulting Psychologists Pr., 1978.

Cita MLA (8th ed.)

Ekman, Paul, i Wallace V. Friesen. Facial Action Coding System. Investigator's Guide: Paul Ekman ; Wallace V. Friesen. Consulting Psychologists Pr., 1978.