1. Ahn, L., Dabbish, L.: Labeling images with a computer game. In: CHI 2004 Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, pp. 319–326 (2004)
2. Bateman, S., Brooks, C., Mccalla, G.: Applying collaborative tagging to e-learning. In: Proceedings of ACM WWW (2007)
3. Dahl, D., Vossen, G.: Evolution of learning folksonomies: social tagging in e-learning repositories. Int. J. Technol. Enhanced Learn. 1, 35–46 (2008)
4. Garcia-Penalvo, F.J., Morales, E., Barron, A.: Learning objects for e-activities in social web. WSEAS Trans. Syst. 6(3), 507–513 (2007)
5. Lecture Notes in Computer Science;V Glavinić,2008