1. Admob. Admob Mobile Metrics Report. https://techcrunch.com/2010/06/30/admob-android-apple/ 2010. Admob. Admob Mobile Metrics Report. https://techcrunch.com/2010/06/30/admob-android-apple/ 2010.
2. App Annie. APP Annie Index: Japan Overtakes U.S. For Google Play Revenues. http://blog.appannie.com/app-annie-index-november-2012/ 2012. App Annie. APP Annie Index: Japan Overtakes U.S. For Google Play Revenues. http://blog.appannie.com/app-annie-index-november-2012/ 2012.
3. BBC News. Social apps 'harvest smartphone contacts' Feb. 2012. http://www.bbc.co.uk/news/technology-17051910. BBC News. Social apps 'harvest smartphone contacts' Feb. 2012. http://www.bbc.co.uk/news/technology-17051910.
4. Reading and estimating gaze on smart phones