R. Neßelrath, and J. Alexandersson. Proceedings of the 6th IJCAI Workshop on Knowledge and Reasoning in Practical Dialogue Systems, Pasadena, CA, USA, page 46-51. (2009)
G. Di Fabbrizio, J. Wilpon, and T. Okken. Proceedings of the 11th International Conference on Multimodal Interfaces and the 6th Workshop on Machine Learning for Multimodal Interfaces (ICMI-MLMI '09), Cambridge, MA, USA, page 71-78. (2009)
P. Lucey, G. Potamianos, and S. Sridharan. Proceedings of AVSP'07: International Conference on Auditory-Visual Speech Processing, Kasteel Groenendaal, Hilvarenbeek, The Netherlands, (2007)