1. Barth, O., Harmonic piezodrive — miniaturized servo motor, Mechatronics, Vol.10 (2000), pp.545-554.
2. Doi, O., Ukai, T., Ochiai, H. and Kudo, H., Tooth profile interference and minimum teeth number of internal involute gear, Bulletin of the Faculty of Engineering, Hokkaido University, No. 81 (1976), pp.1-13 (in Japanese).
3. Hayashi, I., Iwatsuki, N., Kawai, M., Shibata, J. and Kitagawa, T., Development of a piezoelectric cycloid motor, Mechatronics, Vol.2, No.5 (1992), pp.433-444.
4. Ishida, M., Hori, T. and Hanaguchi, J., Principle and operation of the new type motor consisted of piezo-electric device and strain wave gearing, IEEJ Transactions on Industry Applications, Vol.110, No.12 (1990), pp.1247-1256 (in Japanese).
5. Kinki Gear Association ed., Design and Manufacturing of Gears (I) (1971), pp.23-24, TAIGA Publishing (in Japanese).