Hemsel, Tobias, Maik Mracek, Jörg Wallaschek, and Piotr Vasiljev. “A Novel Approach for High Power Ultrasonic Linear Motors.”https://doi.org/10.1109/ULTSYM.2004.1417988__In Ultrasonics Symposium, 2004 IEEE, 2:1161–64, 2004.https://doi.org/10.1109/ULTSYM.2004.1417988 .

Hemsel, Tobias, Walter Littmann, and Jörg Wallaschek. “Piezoelectric Transformers - State of the Art and Development Trends.”https://doi.org/10.1109/ULTSYM.2002.1193485__In Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE, 1:645–48, 2002.https://doi.org/10.1109/ULTSYM.2002.1193485 .

Griebel, P., Georg Lehrenfeld, Wolfgang Müller, C. Tahedl, and H. Uhr. “Integrating a Constraint Solver into a Real-Time Animation Environment.”https://doi.org/10.1109/VL.1996.545262__In Proceedings of the 1996 IEEE Symposium on Visual Languages. Boulder CO, 1996.https://doi.org/10.1109/VL.1996.545262 .

Geiger, Christian, R. Hunstock, Georg Lehrenfeld, Wolfgang Müller, J.https://doi.org/10.1109/VL.1996.545302__Quintanilla, C.https://doi.org/10.1109/VL.1996.545302__Tahedl, and A. Weber. “Visual Modeling and 3D-Representation with a Complete Visual Programming Language --- A Case Study in Manufacturing.”https://doi.org/10.1109/VL.1996.545302__In Proceedings of the 1996 IEEE Symposium on Visual Languages. Boulder, CO, USA, 1996.https://doi.org/10.1109/VL.1996.545302 .