Łapka, Wojciech. “Acoustic Attenuation Performance of a Round Silencer With the Spiral Duct at the Inlet”. Archives of Acoustics 32, no. 4(S) (January 31, 2007): 247–252. Accessed March 22, 2026. https://acoustics.ippt.pan.pl/index.php/aa/article/view/1416.