KHIEM, N. T.; MAI, D. N. Natural frequency analysis of cracked beam. Vietnam Journal of Mechanics, Hanoi, Vietnam, v. 19, n. 2, p. 28–38, 1997. DOI: 10.15625/0866-7136/10052. Disponível em: https://vjs.ac.vn/index.php/vjmech/article/view/10052. Acesso em: 29 jan. 2022.