Batsila, A. (2019). Inter-Learner Communication and Collaborative Learning as Quality Criteria of Distance Vocational Education and Training, European Journal of Open, Distance and E-Learning, 22(2), 15p., 2019.
Ermalai, I.L. (2010). Study cases on e-learning technologies used by universities in Romania and worldwide, WSEAS Transaction on Communication, 8(8), 785-794.
Müller, C., Stahl, M., Alder, M., Müller, M. (2018). Learning Effectiveness and Students’ Perceptions in a Flexible Learning Course, European Journal of Open, Distance and E-Learning, 21(2), 9p, 2018.10.2478/eurodl-2018-0006
Picciano, A. (2017). Theories and Frameworks for Online Education: Seeking and Integrated Model, in J. Online Learning, 21(3), 166-190.10.24059/olj.v21i3.1225