[Brew et al. 2010] Brew, A., Greene, D. and Cunningham, P.: "Using Crowdsourcing and Active Learning to Track Sentiment in Online Media" Coelho, H., Studer, R. and Wooldridge, M., eds.; Proceedings of the 19th European Conference on Artificial Intelligence, IOS Press, Amsterdam, The Netherlands, The Netherlands (2010), 145--150.

[Kohavi 2012] Kohavi, R.: "Online Controlled Experiments: Introduction, Learnings, and Humbling Statistics" (2012).

[Ahn et al. 2007] Ahn, Y.-Y., Han, S., Kwak, H., Moon, S. and Jeong, H.: "Analysis of topological characteristics of huge online social networking services"; Proceedings of the 16th International Conference on World Wide Web, ACM, New York, NY, USA (2007), 835--844.