1. IAB UK—Unlocking the Power of Social Media. Available: http://www.iabuk.net/blog/unlocking-the-power-of-social-media. Accessed 4 July 2013.
2. UMass Dartmouth—2013 Fortune 500. Available: http://www.umassd.edu/cmr/socialmediaresearch/2013fortune500/. Accessed 15 June 2014.
3. How Many People Use Facebook, Twitter and 415 of the Top Social Media, Apps & Tools? Available: http://expandedramblings.com/index.php/resource-how-many-people-use-the-top-social-media/#.Uz0f4Vc4t5E. Accessed 30 April 2014.
4. Solving multiclass learning problems via error-correcting output codes;TG Dietterich;ArXiv Prepr,1995
5. Latent dirichlet allocation;DM Blei;J. Mach. Learn. Res,2003