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)
A. Batliner, C. Hacker, M. Kaiser, H. Mögele, and E. Nöth. Proceedings of AVSP'07: International Conference on Auditory-Visual Speech Processing, Kasteel Groenendaal, Hilvarenbeek, The Netherlands, (2007)
N. Bernsen, and L. Dybkjær. Proceedings of the International CLASS Workshop on Information Presentation and Natural Multimodal Dialogue, Verona, Italy, page 75-79. (2001)
P. Bihler, M. Fotsing, G. Kniesel, and C. Joffroy. iiWAS '08: Proceedings of the 10th International Conference on Information Integration and Web-based Applications & Services, Linz, Austria, page 677-680. (2008)