1. Radio Frequency and Analog/Mixed-Signal Technologies for Wireless Communications 2003 http://www.itrs.com
2. GSM World http://www.gsmworld.com/news/press 2005/press05 21.shtml
3. C. Ambrosio Global Handset Sales Historical and Forecasts 2002-2011 2006 http://www.strategyanalytics.com
4. Telemedicine Information Exchange http://tie.telemed.org