PAJEWSKI, W., KIEŁCZYŃSKI, P. and SZALEWSKI, M. (1995) “Radiation of piezoelectric rings into the air through cylindrical waveguides”, Archives of Acoustics, 20(4), pp. 361–372. Available at: http://acoustics.ippt.gov.pl/index.php/aa/article/view/1276 (Accessed: 18 April 2026).