TETT, M. Legacy Telecommunication Systems. Journal of Telecommunications and the Digital Economy, [S. l.], v. 3, n. 4, p. 63–65, 2015. DOI: 10.18080/jtde.v3n4.40. Disponível em: https://mail.jtde.telsoc.org/index.php/jtde/article/view/40. Acesso em: 4 jul. 2024.