1. Facebook features. http://en.wikipedia.org/wiki/Facebook_features. Facebook features. http://en.wikipedia.org/wiki/Facebook_features.
2. Facebook's growth since ipo in 12 big numbers. http://techcrunch.com/2013/05/17/facebook-growth/. Facebook's growth since ipo in 12 big numbers. http://techcrunch.com/2013/05/17/facebook-growth/.
3. How big is facebook's data? http://techcrunch.com/2012/08/22/how-big-is-facebooks-data-2-5-billion-pieces-of-content-and-500/-terabytes-ingested-every-day/. How big is facebook's data? http://techcrunch.com/2012/08/22/how-big-is-facebooks-data-2-5-billion-pieces-of-content-and-500/-terabytes-ingested-every-day/.
4. Semantic similarity. http://en.wikipedia.org/wiki/Semantic_similarity. Semantic similarity. http://en.wikipedia.org/wiki/Semantic_similarity.
5. Analyzing user modeling on twitter for personalized news recommendations. In User Modeling;Abel F.;Adaption and Personalization. Springer,2011