OBOT, O. W.; ITE, O. O.; BEN, J. M. Variant Design and Fabrication of an Earth Tunneling Machine. European Journal of Engineering and Technology Research, [S. l.], v. 3, n. 3, p. 63–66, 2018. DOI: 10.24018/ejeng.2018.3.3.421. Disponível em: https://ej-eng.org/index.php/ejeng/article/view/421. Acesso em: 4 jul. 2024.