Filloux, Frederick (15 June 2011). "Analyzing the metered model". Monday Note. Archived from the original on 18 October 2011. Retrieved 13 October 2011.
Rosenstiel, Tom (17 October 2008). "Survey: Mobile News & Paying Online". The State of the News Media 2011. Pew Research Center’s Project for Excellence in Journalism. Archived from the original on 12 October 2011. Retrieved 12 October 2011.
Filloux, Frederick (15 June 2011). "Analyzing the metered model". Monday Note. Archived from the original on 18 October 2011. Retrieved 13 October 2011.
Rosenstiel, Tom (17 October 2008). "Survey: Mobile News & Paying Online". The State of the News Media 2011. Pew Research Center’s Project for Excellence in Journalism. Archived from the original on 12 October 2011. Retrieved 12 October 2011.