GOLANOWSKI, Jerzy, and Tadeusz GUDRA. “Ultrasonic Transducers Using Radial Vibrations of a Piezoelectric Disk”. Archives of Acoustics 4, no. 3 (March 7, 2016): 245–255. Accessed April 26, 2025. https://acoustics3.ippt.pan.pl/index.php/aa/article/view/3380.