"European Publishing Monitor"(PDF). Turku School of Economics (Media Group). March 2007. Archived from the original(Report) on 10 October 2017. Retrieved 25 April 2015.
"European Publishing Monitor"(PDF). Turku School of Economics (Media Group). March 2007. Archived from the original(Report) on 10 October 2017. Retrieved 25 April 2015.