J. PIECHOWICZ and I. CZAJKA, “Estimation of Acoustic Impedance for Surfaces Delimiting the Volume of an Enclosed Space”, Arch. Acoust., vol. 37, no. 1, pp. 97–102, Oct. 2013, Accessed: Apr. 28, 2025. [Online]. Available: https://acoustics3.ippt.pan.pl/index.php/aa/article/view/132