1. De Freitas, S.: Serious Virtual Worlds – A scoping study. JISC (2008)
2. Brooke, J.: SUS: A quick and dirty usability scale. In: Jordan, P.W., Thomas, B., Weerdmeester, B.A., McClelland, A.L. (eds.) Usability Evaluation in Industry, Taylor and Francis (1996)
3. Onlabs @ Hellenic Open University,
https://sites.google.com/site/onlabseap/
4. Aggelopoulou, N., Pierrakeas, C., Artikis, A., Kalles, D.: Ontological Modelling for Intelligent e-Learning. In: 14th IEEE International Conference on Advanced Learning Technologies, Athens, Greece (2014)