C. Endres, T. Schwartz, and C. Müller. Proceedings of IUI '11: 16th International Conference on Intelligent User Interfaces, Palo Alto, CA, USA, page 327-330. (2011)
M. Phillips, J. Nguyen, and A. Mischke. Advances in Speech Recognition: Mobile Environments, Call Centers and Clinics, chapter 3, Springer, New York, (2010)
R. Neßelrath, and J. Alexandersson. Proceedings of the 6th IJCAI Workshop on Knowledge and Reasoning in Practical Dialogue Systems, Pasadena, CA, USA, page 46-51. (2009)