10th Annual report 2003 [documento electrónico] / Belgian Institute of Postal Services and Telecommunications
Posts and telecommunications in Japan 2001 : annual report / Ministry of Public Management, Home Affairs, Posts and Telecommunications
Kommunikationsbericht 2007 / Rundfunk & Telekom Regulierungs - GMBH
Kommunikationsbericht 2008 / Rundfunk & Telekom Regulierungs - GMBH