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 November 9, 2025. https://vjmech.vast.vn/vjmech/article/view/9693.