J. Kim, P. Guo, D. Seaton, P. Mitros, K. Gajos, and R. Miller. Proceedings of the First ACM Conference on Learning @ Scale Conference, page 31–40. New York, NY, USA, Association for Computing Machinery, (2014)
B. Miller, J. Riedl, and J. Konstan. From Usenet to CoWebs - Interacting with Social Information Spaces, Springer, London, Computer-Supported Cooperative Work.(2003)