J. Chang, and M. Bourguet. Proceedings of the 22Nd British HCI Group Annual Conference on People and Computers: Culture, Creativity, Interaction - Volume 2, page 123--126. Swinton, UK, UK, British Computer Society, (2008)
S. Balbo, D. Draheim, C. Lutteroth, and G. Weber. Proceedings of the 4th international workshop on Task models and diagrams, page 111--118. New York, NY, USA, ACM, (2005)
S. Oviatt, R. Coulston, and R. Lunsford. Proceedings of the 6th international conference on Multimodal interfaces, page 129--136. New York, NY, USA, ACM, (2004)