Eckes, C., Biatov, K., Hülsken, F., Köhler, J., Breuer, P., Branco, P. and Encarnacao, . L. M. (2007) “Towards Sociable Virtual Humans: Multimodal Recognition of Human Input and Behavior”, International Journal of Virtual Reality, 6(4), pp. 21–30. doi: 10.20870/IJVR.2007.6.4.2705.