Z. KLESZCZEWSKI, “Making use of Bragg’s diffraction for investigations of the acoustic activity of bismuth-germanium oxide”, Arch. Acoust., vol. 15, no. 3-4, pp. 367–374, May 2014, Accessed: Jan. 17, 2026. [Online]. Available: https://acoustics.ippt.gov.pl/index.php/aa/article/view/1295