Chi Long, Nguyen, and Le Khanh Luan. “THE SEMIGROUP CHARACTERIZATION OF THE VIBRATION OF THE CURVED SURFACE OF A BRIDGE”. Science and Technology Development Journal 2, no. 11&12 (December 31, 1999): 75-86. Accessed May 19, 2024. http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/3698.