1. Y. Zhang, J. Hesselbach, and H. Kerle, VDI-Mechatronik-Tagung, 12–13 September 2001, Frankenthal, Germany (unpublished), pp. 465–481.
2. Y. Zhang, dissertation, TU Braunschweig, 2001.
3. Aktoren
4. S. Brand, dissertation, Universität Hannover, 1996.