TRYNKOWSKA, Danuta, and Ryszard MICHALSKI. “Relation of Ear Protector Attenuation to Noise Spectra and Methods for Its Determination”. Archives of Acoustics 4, no. 3 (March 7, 2016): 205–219. Accessed April 28, 2025. https://acoustics3.ippt.pan.pl/index.php/aa/article/view/3378.