Anna Nedyalkova and KrassimirNedyalkov and TeodoraBakardjieva, Social Software Approach to E-Learning 3.0. journal = {International Journal of Educational and Pedagogical Sciences}, [online]. World Academy of Science, Engineering and Technology. March 2013, vol. 75(3). 558 - 561 [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/3269.