1. Bar-Cohen, Y., Bao, X., Grandia, W., 1998. Rotary Ultrasonic Motors Actuated by Traveling Flexural Waves. Proceedings of the SPIE International Smart Materials and Structures Conference, San Diego, CA, 3329:794–780.
2. Chen, Y., Lu, K., Zhou, T.Y., Liu, T., Lu, C.Y., 2006. Study of a mini-ultrasonic motor with square metal bar and piezoelectric plate hybrid. Jpn. J. Appl. Phys., 45(5B):4780–4781. [doi:10.1143/JJAP.45.4780]
3. Duan, W.H., Quek, S.T., Lim, S.P., 2005. Finite element analysis of a ring type ultrasonic motor. Proc. of SPIE, 5757:575–586. [doi:10.1117/12.597983]
4. Frangi, A., Corigliano, A., Binci, M., Faure, P., 2005. Finite element modelling of a rotating piezoelectric ultrasonic motor. Ultrasonics, 43(9):747–755. [doi:10.1016/j.ultras.2005.04.005]
5. Glenn, T.S., 2002. Mixed-domain Performance Model of the Piezoelectric Traveling-wave Motor and the Development of a Two-Sided Device. Ph.D Thesis, MIT.