“…The second discipline is related to COVID research, which has been classified into three sub-disciplines, mainly pre-COVID-19 [37], [62], [63], [64], [65], COVID-19 [6], [21], [38], [40], [54], [66], [67] and post-COVID-19 [7], [8], [10], [11], [13], [14], [15], [16], [18], [27], [28], [39], [41], [42], [54], [66], [67], [68], [69], [70], [71], [72], [73], [74], [75], [76]. Before and during COVID-19, learning had shifted from traditional classroom settings to blended and virtual ones [54].…”