Anh, Nguyen Dong, and Nguyen Duc Tinh. “On the Influence of Second Order Non-Linearity on Random Vibrations”. <i>Vietnam Journal of Mechanics</i> 20, no. 4 (December 30, 1998): 1–10. Accessed November 9, 2025. https://vjmech.vast.vn/vjmech/article/view/10036.