U. Andreaus, P. Casini, and F. Vestroni, “Frequency Reduction in Elastic Beams Due to a Stable Crack: Numerical Results Compared with Measured Test Data”, Eng. Trans., vol. 51, no. 1, pp. 87–101, Mar. 2015, Accessed: Apr. 24, 2025. [Online]. Available: https://et3.ippt.pan.pl/index.php/et/article/view/502