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)
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. 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)
V. Penichet, M. Lozano, J. Gallud, and R. Tesoriero. Proceedings of the 6th international conference on Task models and diagrams for user interface design, page 287--292. Berlin/Heidelberg, Springer-Verlag, (2007)