Y. Wang, and S. Hamerich. Recent Trends in Discourse and Dialogue, volume 39 of Text, Speech and Language Technology, chapter 2, Springer, Dordrecht, (2008)
Y. Wang, S. Hamerich, M. Hennecke, and V. Schubert. Proceedings of the 6th Workshop of the Special Interest Group on Discourse and Dialogue (SIGdial 2005), Lisbon, Portugal, page 217--221. (2005)
H. Zha. Proceedings of the 25th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, page 113-120. Tampere, Finland, (2002)