BARRELL, Kevin; LEMMENS, Warren. The Future of Digital Services Delivery. Journal of Telecommunications and the Digital Economy, [S. l.], v. 3, n. 3, p. 31–46, 2015. DOI: 10.18080/jtde.v3n3.22. Disponível em: https://www.jtde.telsoc.org/index.php/jtde/article/view/22. Acesso em: 26 oct. 2025.