M. PIECHOCKI, “Bi-directional continuous wave doppler flowmeter and its application in investigations of disturbed blood flows”, Arch. Acoust., vol. 11, no. 1, pp. 75–88, Mar. 1986, Accessed: Mar. 04, 2026. [Online]. Available: https://acoustics.ippt.gov.pl/index.php/aa/article/view/3110