CHI, T. K. Non-linear oscillations of pendulum with vertically moving multifrequency support point. Vietnam Journal of Mechanics, Hanoi, Vietnam, v. 16, n. 1, p. 9–14, 1994. DOI: 10.15625/0866-7136/10149. Disponível em: https://vjs.ac.vn/index.php/vjmech/article/view/10149. Acesso em: 25 apr. 2024.