Renzel, D., C. Höbelt, D. Dahrendorf, M. Friedrich, F. Mödritscher, K. Verbert, S. Govaerts, M. Palmér, and E. Bogdanov. 2010. “Collaborative Development of a PLE for Language Learning”. International Journal of Emerging Technologies in Learning (iJET) 5 (SI1):pp. 31-40. https://doi.org/10.3991/ijet.v5iSI1.1196.