KHIEM, N. T. An approach to study vibration in stochastic systems based on the asymptotic method. Vietnam Journal of Mechanics, Hanoi, Vietnam, v. 29, n. 3, p. 375–384, 2007. DOI: 10.15625/0866-7136/29/3/5546. Disponível em: https://vjs.ac.vn/index.php/vjmech/article/view/5546. Acesso em: 25 may. 2022.