Matlakala, Mmatlou, et al. “An Empirical Study on the Predictors of the Perceived Quality of Learning at Institutions of Higher Education: 2D Model Approach”. International Journal of Emerging Technologies in Learning (iJET), vol. 14, no. 15, Aug. 2019, pp. pp. 67-77, doi:10.3991/ijet.v14i15.10608.