MARKOWITZ JR., Harold. The Next Twenty Years in American Independent Study. International Journal of E-Learning & Distance Education / Revue internationale du e-learning et la formation à distance, [S. l.], v. 3, n. 1, p. 89–93, 1988. Disponível em: https://ijede.ca/index.php/jde/article/view/539. Acesso em: 27 apr. 2024.