1) J. G. Woodward, “A vibrating-plate viscomester,” J Acoust. Soc. Am. 25,147-151 (1953).
2) K. Negishi, “Measurement of viscosity by vibration,” in Ultrasonic Technology (Nihon Kogyo Shuppan, Tokyo, 1995), Vol.7, No.2, pp.15-18 (in Japanese).
3) T. Kobayashi, “Viscometer using a bimorph transducer,” in Ultrasonic Technology (Nihon Kogyo Shuppan, Tokyo, 1995), Vol.7, No.3, pp.11-16 (in Japanese).
4) Y. Torikai and K. Negishi, “Measurement of the viscosity of liquids by a torsional crystal,” Jpn. Soc. Appl. Phys. 25,158-163 (1956)(in Japanese).
5) T. Ito, M. Kawano, and T. Kobayashi, “Viscometer by phase difference method using a bimorph transducer-The phase difference characteristics for the shapes of bimorph transducer-,” Proc. Spring Meet. Acoust. Soc. Jpn., 1073-1074 (1996)(in Japanese).