S. Bergweiler, M. Deru, and D. Porta. ACM International Conference on Interactive Tabletops and Surfaces, page 245--246. New York, NY, USA, ACM, (2010)
G. Di Fabbrizio, J. Wilpon, and T. Okken. Proceedings of the 11th International Conference on Multimodal Interfaces and the 6th Workshop on Machine Learning for Multimodal Interfaces (ICMI-MLMI '09), Cambridge, MA, USA, page 71-78. (2009)
D. Porta, D. Sonntag, and R. Neßelrath. Proceedings of the 11th International Conference on Human-Computer Interaction with Mobile Devices and Services. MobileHCI-09, September 15 - August 18, Bonn, Germany, ACM, (2009)
M. Johnston. Proceedings of the 11th International Conference on Multimodal Interfaces and the 6th Workshop on Machine Learning for Multimodal Interfaces (ICMI-MLMI '09), Cambridge, MA, USA, page 47-54. (2009)