TUROFF, Murray. Costs for the Development of a Virtual University. Online Learning, Boston, MA, v. 1, n. 1, 1997. DOI: 10.24059/olj.v1i1.1943. Disponível em: https://olj.onlinelearningconsortium.org/index.php/olj/article/view/1943. Acesso em: 28 jul. 2026.