Märtens, O., T. Saar, and M. Reidla. “Study of Various Excitation and Reference Signals for Pulsed Correlation-Based Ultrasound Signal Processing”. Elektronika ir Elektrotechnika 105, no. 9 (October 29, 2010): 89-92. Accessed December 6, 2021. https://eejournal.ktu.lt/index.php/elt/article/view/9185.