DINH, Nguyen Van. The Van der Pol’s system under external and parametric excitations. <b>Vietnam Journal of Mechanics</b>, Hanoi, Vietnam, v. 19, n. 1, p. 27–33, 1997. DOI: 10.15625/0866-7136/10045. Disponível em: https://vjmech.vast.vn/vjmech/article/view/10045. Acesso em: 9 nov. 2025.