ANH, Nguyen Dong; KHIEM, Nguyen Tien. Sub harmonic oscillations in first order systems with delay. <b>Vietnam Journal of Mechanics</b>, Hanoi, Vietnam, v. 12, n. 1, p. 1–6, 1990. DOI: 10.15625/0866-7136/10272. Disponível em: https://vjs.ac.vn/vjmech/article/view/10272. Acesso em: 5 dec. 2025.