1. R.Y. Bansevichyus, K.M. Ragulskis. Vibration motors as precision units for manipulators and robots, Mach. Tool. 49(8), 23–27 (1978)
2. Y. Tomikawa, T. Takano, H. Umeda. Thin rotary and linear ultrasonic motors using a double-mode piezoelectric vibrator of the first longitudinal and second bending modes, Jpn. J. Appl. Phys. 31(9B), 3073–3076 (1992)
3. S. Ueha, Y. Tomikawa, Ultrasonic Motors Theory and Applications. (Oxford Science Publications, Clarendon Press, Oxford, 1993)
4. P. Vasiljev, in Proceedings of the 7th International Conference on New Actuators 2002, Actuator of Type “a Shaking Beam,” Bremen, Germany, 2002
5. W. Littmann, T. Hemsel, C. Kauczor, in Proceedings of the World Congress of Ultrasonics, Load-adaptive Phase-controller for Resonant Driven Piezoelectric Devices, Paris, 2003