O. PIDDUBNIAK, “Total scattering cross-section of a nondeformable sphere partially insonified at a circular annular spot”, Arch. Acoust., vol. 22, no. 3, pp. 297–306, Jan. 2014, Accessed: Apr. 28, 2025. [Online]. Available: https://acoustics3.ippt.pan.pl/index.php/aa/article/view/956