LE, Nguyen Nhat. Optimal control of systems with time delays. <b>Vietnam Journal of Mechanics</b>, Hanoi, Vietnam, v. 14, n. 3, p. 13–19, 1992. DOI: 10.15625/0866-7136/10235. Disponível em: https://vjs.ac.vn/vjmech/article/view/10235. Acesso em: 5 dec. 2025.