DINH, N. V. A note on the Melnikov function. Vietnam Journal of Mechanics, Hanoi, Vietnam, v. 29, n. 3, p. 285–291, 2007. DOI: 10.15625/0866-7136/29/3/5540. Disponível em: https://vjs.ac.vn/index.php/vjmech/article/view/5540. Acesso em: 29 mar. 2024.