Khoa, Nguyen Viet, and Nguyen Van Quang. “Free Vibration of a Cracked Double-Beam Carrying a Concentrated Mass”. Vietnam Journal of Mechanics 38, no. 4 (December 20, 2016): 279–293. Accessed November 8, 2025. https://vjmech.vast.vn/vjmech/article/view/7118.