PIOTRZKOWSKA H, LITNIEWSKI J, SZYMAŃSKA E, NOWICKI A. Ultrasonic Echosignal Applied to Human Skin Lesions Characterization. Arch. Acoust. 2012;37(1):103–108. Accessed March 4, 2026. https://acoustics.ippt.gov.pl/index.php/aa/article/view/133