1. US Federal Communication Commission FCC 2008
2. Ofcom, Implementing Geolocation http://stakeholders.ofcom.org.uk/consultations/geolocation 2010
3. 2010
4. M. Mishra A. Sahai 2009 http://www.eecs.berkeley.edu/Pubs/TechRpts/2009/EECS-2009-3.html
5. http://www.itu.int/ITU-D/tech/digital_broadcasting/Reports/DigitalDividend.pdf