RDZANEK, W. P. Jr., and Z. ENGEL. “Directional Characteristics of a Planar Annular Plate for Axially-Symmetric Free Vibrations”. Archives of Acoustics 25, no. 1 (January 1, 2000): 73–81. Accessed January 17, 2026. https://acoustics.ippt.gov.pl/index.php/aa/article/view/354.