A. Arthur, R. Lunsford, M. Wesson, and S. Oviatt. Proceedings of the 8th international conference on Multimodal interfaces, page 209--216. New York, NY, USA, ACM, (2006)
A. Dittmar, and P. Forbrig. Interactive Systems. Design, Specification, and Verification, volume 2844 of Lecture Notes in Computer Science, chapter 13, Springer-Verlag, Berlin/Heidelberg, (2003)
F. Paternò, C. Mancini, and S. Meniconi. Proceedings of the IFIP TC13 Interantional Conference on Human-Computer Interaction, page 362--369. London, UK, UK, Chapman & Hall, Ltd., (1997)
A. Dittmar, and P. Forbrig. Proceedings of the 6th international conference on Task models and diagrams for user interface design, page 198--212. Berlin/Heidelberg, Springer-Verlag, (2007)