J. Chen, W. Geyer, C. Dugan, M. Muller, and I. Guy. Proceedings of the 27th international conference on Human factors in computing systems, page 201--210. New York, NY, USA, ACM, (2009)
S. Fazeli, B. Loni, H. Drachsler, and P. Sloep. Open Learning and Teaching in Educational Communities, volume 8719 of Lecture Notes in Computer Science, Springer International Publishing, (2014)
L. Gou, H. Chen, J. Kim, X. Zhang, and C. Giles. Proceedings of the 19th International Conference on World Wide Web, page 1103--1104. New York, NY, USA, ACM, (2010)
G. Groh, S. Birnkammerer, and V. Köllhofer. Recommender Systems for the Social Web, volume 32 of Intelligent Systems Reference Library, chapter 1, Springer Berlin Heidelberg, Berlin, Heidelberg, (2012)
G. Groh, S. Birnkammerer, and V. Köllhofer. Recommender Systems for the Social Web, volume 32 of Intelligent Systems Reference Library, chapter 1, Springer Berlin Heidelberg, Berlin, Heidelberg, (2012)
G. Groh, and C. Ehmig. GROUP '07: Proceedings of the 2007 international ACM conference on Supporting group work, page 127--136. New York, NY, USA, ACM, (2007)
G. Groh, and C. Ehmig. GROUP '07: Proceedings of the 2007 international ACM conference on Supporting group work, page 127--136. New York, NY, USA, ACM, (2007)