OPIELIŃSKI, Krzysztof J., Tadeusz GUDRA, and Piotr PRUCHNICKI. 2013. “A Digitally Controlled Model of an Active Ultrasonic Transducer Matrix for Projection Imaging of Biological Media”. Archives of Acoustics 35 (1): 75-90. https://acoustics3.ippt.pan.pl/index.php/aa/article/view/258.