D. Lalanne, L. Nigay, P. Palanque, P. Robinson, J. Vanderdonckt, and J. Ladr. IMCI-MLMI '09: Proceedings of the 11th International Conference on Multimodal Interfaces and the 6th Workshop on Machine Learning for Multimodal Interfaces, Cambridge, MA, USA, page 153-160. (2009)
D. Milward, and M. Beveridge. Proceedings of the 3rd IJCAI Workshop on Knowledge and Reasoning in Practical Dialogue Systems, Acapulco, Mexico, page 9-18. (2003)