Menh, Nguyen Cao, Nguyen Tien Khiem, Dao Nhu Mai, and Nguyen Viet Khoa. “Modal Analysis of Damaged Structures by the Modified Finite Element Method”. Vietnam Journal of Mechanics 20, no. 1 (March 30, 1998): 29–46. Accessed April 20, 2024. https://vjs.ac.vn/index.php/vjmech/article/view/10010.