LI, Haoran, Yan HU, Laibo LI, and Dongyu XU. “Acoustic Matching Characteristics of Annular Piezoelectric Ultrasonic Sensor”. Archives of Acoustics 47, no. 2 (May 25, 2022): 275–284. Accessed June 21, 2025. https://acoustics.ippt.pan.pl/index.php/aa/article/view/3443.