“…The three most common principal subjects in the 39 reviewed papers were: exercises to define and describe e-learning as a concept (Adam et al, 2013;Al Zahrani & Kumar, 2015;Cardona-Román & Sánchez-Torres, 2011;Crescente & Lee, 2011;Denham et al, 2012;Grant, 2019;Hartley & Andújar, 2022;Ismuratova et al, 2017;Kergel & Heidkamp-Kergel, 2021;Khoury et al, 2011;Kumar Basak et al, 2018;Li, 2018;Mirmoghtadaie et al, 2019;Moore et al, 2011;Nagy, 2016;Rodrigues et al, 2019;Vagarinho, 2020;Vagarinho, 2018)); descriptions of the concept or implementation of specific e-learning programmes (Al-rahmi et al, 2015;Arzayeva et al, 2015;Kobewka et al, 2014;Launay-Vacher & Rieutord, 2014;Lewis et al, 2014;Martínez-Gómez et al, 2022); and, the use of artificial intelligence, machine learning, or semantic web technology to suggest and provide learning objects based on a learner's requirements (Ahmed et al, 2018;Kavitha & Lohani, 2019;Moubayed et al, 2018;Sengupta et al, 2021).…”