1. Social Network Sites: Definition, History, and Scholarship
2. Social media definition and the governance challenge: An introduction to the special issue
3. Statista20172017-10-30Global social media ranking 2017
https://www.statista.com/statistics/272014/global-social-networks-ranked-by-number-of-users/
4. FacebookCompany Info
https://newsroom.fb.com/company-info/
5. Twitter20172017-10-30https://about.twitter.com/company