ŁAPKA, Wojciech. Insertion Loss of Spiral Ducts - Measurements and Computations. Archives of Acoustics, [S. l.], v. 34, n. 4, p. 537–545, 2014. Disponível em: https://acoustics3.ippt.pan.pl/index.php/aa/article/view/594. Acesso em: 26 apr. 2025.