Bich, Dao Huy, Nguyen Dang Bich, and Nguyen Anh Tuan. “On the Solutions of the Mathieu’s Equation”. Vietnam Journal of Mechanics 30, no. 4 (December 31, 2008): 219 –. Accessed March 29, 2024. https://vjs.ac.vn/index.php/vjmech/article/view/5627.