TRU, V. Q.; BICH, N. D. On the instability of a mechanical system of 2-degree of freedom taking into account the resisting force. Vietnam Journal of Mechanics, Hanoi, Vietnam, v. 19, n. 4, p. 73–78, 1997. DOI: 10.15625/0866-7136/10070. Disponível em: https://vjs.ac.vn/index.php/vjmech/article/view/10070. Acesso em: 23 apr. 2024.