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Levenson, R. W., Ekman, P., Heider, K. & Friesen, W. V. 1992. «Emotion and autonomic nervous system activity in the Minangkabau of West Sumatra». Journal of Personality and Social Psychology, 62: 972-988. Levenson, R. W., Carstensen, L. L., Friesen, W. V. & Ekman, P. 1991. «Emotion, physiology, and expression in old age». Psychology and Aging, 6: 28-35. Levenson, R. W., Ekman,P. & Friesen, W. V. 1990. «Voluntary facial action generates emotion-specific autonomic nervous system activity». Psychophysiology, 27: 363-384. Ekman, P., Levenson, R. W. & Friesen, W. V. 1983. «Autonomic nervous system activity distinguishes between emotions». Science, 221:1208-1210.