Menh, Nguyen Cao, Nguyen Tien Khiem, Dao Nhu Mai, and Nguyen Viet Khoa. “Modal Analysis of Damaged Structures by the Modified Finite Element Method”. <i>Vietnam Journal of Mechanics</i> 20, no. 1 (March 30, 1998): 29–46. Accessed November 8, 2025. https://vjmech.vast.vn/vjmech/article/view/10010.