1. Fuchs, M.: Multi-modal user interface (in Czech). Master thesis, Department of Computer Science and Engineering, FEE, Czech Technical University Prague (1999).
2. Hejda, P.: Dialog Markup Language. Poster99, FEE, Czech Technical University in Prague (1999) IC8.
3. Hejda, P.: Situations in Dialogue. In Text, Speech and Dialogue. Springer-Verlag, Berlin Heidelberg New York (1999) 290–295.
4. Larson, J. A.: Interactive Software. Yourdon Press (1992).