Dong, Dang Thuy, and Dao Van Dung. “Nonlinear Vibration of Functionally Graded Material Sandwich Doubly Curved Shallow Shells Reinforced by FGM Stiffeners. Part 2: Numerical Results and Discussion”. Vietnam Journal of Mechanics 39, no. 4 (December 27, 2017): 329–338. Accessed April 26, 2024. https://vjs.ac.vn/index.php/vjmech/article/view/9693.