WASZCZUK, T., T. KUJAWSKA, and J. C. SOMER. “Electronic Focusing of the Ultrasonic Beam by Means of an Annular Array System”. Archives of Acoustics 9, no. 1-2 (July 10, 2015): 155–162. Accessed April 26, 2025. https://acoustics3.ippt.pan.pl/index.php/aa/article/view/3208.