Y. Wang, and S. Hamerich. Recent Trends in Discourse and Dialogue, volume 39 of Text, Speech and Language Technology, chapter 2, Springer, Dordrecht, (2008)
R. Pieraccini, and J. Huerta. Recent Trends in Discourse and Dialogue, volume 39 of Text, Speech and Language Technology, chapter 1, Springer, Dordrecht, (2008)