Cita APA (7th ed.)

Ekman, P. Duchenne and facial expression of emotion: Paul Ekman. The mechanism of human facial expression.(2003).

Cita Chicago (17th ed.)

Ekman, Paul. "Duchenne and Facial Expression of Emotion: Paul Ekman." The Mechanism of Human Facial Expression.(2003) .

Cita MLA (8th ed.)

Ekman, Paul. "Duchenne and Facial Expression of Emotion: Paul Ekman." The Mechanism of Human Facial Expression.(2003), .