H. Nguyen, N.-P. Nguyen, X.-Q. Nguyen, and A.-D. Le, “[RETRACTED] An Approach to Optimize the Design of Ultrasonic Transducer for Food Dehydration”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 11, no. 3, pp. 1125–1131, Jun. 2021.