DINH, N. V. Stationary oscillations in degenerated case. Vietnam Journal of Mechanics, Hanoi, Vietnam, v. 18, n. 2, p. 13–19, 1996. DOI: 10.15625/0866-7136/10094. Disponível em: https://vjs.ac.vn/vjmech/article/view/10094. Acesso em: 26 apr. 2025.