Murphy, Elizabeth, and María A. Rodríguez-Manzanares. “Teachers’ Perspectives on Motivation in High-School Distance Education”. International Journal of E-Learning & Distance Education Revue Internationale Du E-Learning Et La Formation à Distance, vol. 23, no. 3, Nov. 2009, pp. 1-24, https://www.ijede.ca/index.php/jde/article/view/602.