DINH, N. V.; CHI, T. K. A system of Van der Pol type under nonlinear parametric excitation. Vietnam Journal of Mechanics, Hanoi, Vietnam, v. 19, n. 4, p. 21–28, 1997. DOI: 10.15625/0866-7136/10064. Disponível em: https://vjs.ac.vn/index.php/vjmech/article/view/10064. Acesso em: 27 apr. 2024.