Khalid, Asra, Karsten Lundqvist, and Anne Yates. “Recommender Systems for MOOCs: A Systematic Literature Survey (January 1, 2012 – July 12, 2019)”. The International Review of Research in Open and Distributed Learning 21, no. 4 (June 19, 2020): 255–291. Accessed April 24, 2024. https://www.irrodl.org/index.php/irrodl/article/view/4643.