Ekman, P. Duchenne and facial expression of emotion: Paul Ekman. The mechanism of human facial expression.(2003).
Lua i Stíl Chicago (17ú heag.)Ekman, Paul. "Duchenne and Facial Expression of Emotion: Paul Ekman." The Mechanism of Human Facial Expression.(2003) .
Lua MLA (8ú heag.)Ekman, Paul. "Duchenne and Facial Expression of Emotion: Paul Ekman." The Mechanism of Human Facial Expression.(2003), .
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