1. Cornelius, R.R.: Theoretical approaches to emotion. In: ISCA Workshop on Speech and Emotion, Belfast (2000)
2. Sander, D., Grandjean, D., Scherer, K.R.: A systems approach to appraisal mechanisms in emotion. In: Neural Networks, pp. 317–352. Elsevier, Amsterdam (2005)
3. Ekman, P., et al.: Universals and cultural differences in the judgments of facial expressions of emotion. Journal of Personality and Social Psychology, 712–717 (1987)
4. Cowie, R.: Describing the emotional states expressed in speech. In: ISCA Workshop on Speech and Emotion, Northern Ireland (2000)
5. Cowie, R., et al.: Emotion recognition in human computer interaction. IEEE Signal Processing Magazine, 32–80 (2001)