Ekman, P. Expression and the nature of emotion: Paul Ekman. Approaches to emotion.(c 1984).
Citazione stile Chigago Style (17a edizione)Ekman, Paul. "Expression and the Nature of Emotion: Paul Ekman." Approaches to Emotion.(c 1984) .
Citatione MLA (8a ed.)Ekman, Paul. "Expression and the Nature of Emotion: Paul Ekman." Approaches to Emotion.(c 1984), .
Attenzione: Queste citazioni potrebbero non essere precise al 100%.