de la Varre, Claire, et al. “Dual Perspectives on the Contribution of On-Site Facilitators to Teaching Presence in a Blended Learning Environment”. International Journal of E-Learning & Distance Education Revue Internationale Du E-Learning Et La Formation à Distance, vol. 25, no. 3, Nov. 2011, https://www.ijede.ca/index.php/jde/article/view/751.