BANDERA, W., and K. PAWLACZYK. “Sound Velocity and Loss Factor of Polyurethane Composites. Part I”. Archives of Acoustics 16, no. 3-4 (December 31, 1991): 433–449. Accessed April 18, 2026. http://acoustics.ippt.gov.pl/index.php/aa/article/view/1240.