A. Oulasvirta, S. Tamminen, V. Roto, and J. Kuorelahti. Proceedings of the SIGCHI conference on Human factors in computing systems, page 919--928. Portland, Oregon, USA, ACM, (2005)
A. Jameson, and K. Klöckner. Spoken Multimodal Human-Computer Dialogue in Mobile Environments, volume 28 of Text, Speech and Language Technology, chapter 19, Springer-Verlag, Berlin/Heidelberg, (2005)