1. UN Department of Economic and Social Affairs
http://www.un.org/esa/population/publications/worldageing19502050/
2. eHealth for Patient Empowerment in Europe, 2009
http://ec.europa.eu
3. Emerging Wireless LANs, Wireless PANs, and Wireless MANs;Xiao,2009
4. Fundamentals of Wireless Sensor Networks Theory and Practice;Dargie,2010