Yu, A. C. H., K. W. Johnston, and R. S. C. Cobbold. “Frequency-Based Signal Processing for Ultrasound Color Flow Imaging”. Canadian Acoustics, vol. 35, no. 2, June 2007, pp. 11-23, https://jcaa.caa-aca.ca/index.php/jcaa/article/view/1874.