F. Narita, Y. Shindo, F. Saito, and M. Mikami, “Testing and analysis of high frequency electroelastic characteristics of piezoelectric transformers”, Arch. Mech., vol. 59, no. 2, pp. 119–131, Mar. 2007, Accessed: Jan. 17, 2026. [Online]. Available: http://am.ippt.gov.pl/index.php/am/article/view/v59p119