M. Johnston, S. Bangalore, A. Stent, G. Vasireddy, and P. Ehlen. Proceedings of ICSLP---Interspeech 2002: 7th International Conference on Spoken Language Processing, Denver, CO, USA, page 2237-2240. (2002)
J. Allen, G. Ferguson, and A. Stent. Proceedings of IUI '01: 6th International Conference on Intelligent User Interfaces, Santa Fe, NM, USA, page 1-8. (2001)