ALKAFF, A.; QOMARUDIN, M. N.; ALKAFF, S. D.; BILFAQIH, Y. Modelling Online Course Services and Comparison of its Major Providers. International Journal of Emerging Technologies in Learning (iJET), [S. l.], v. 13, n. 01, p. pp. 65–81, 2018. DOI: 10.3991/ijet.v13i01.7528. Disponível em: https://online-journals.org/index.php/i-jet/article/view/7528. Acesso em: 22 jan. 2022.