KHIEM, N. T. Spectral analysis of vibration in weakly non-linear systems. Vietnam Journal of Mechanics, Hanoi, Vietnam, v. 22, n. 3, p. 181–192, 2000. DOI: 10.15625/0866-7136/9974. Disponível em: https://vjs.ac.vn/index.php/vjmech/article/view/9974. Acesso em: 25 apr. 2024.