Qing Zhou Depeng Jin Lieguang Zeng Yuwen Zhou Area Concentric Beacons Localization for Wireless Sensor Networks. 2129-2134 2008 WCNC http://dx.doi.org/10.1109/WCNC.2008.377 conf/wcnc/2008 db/conf/wcnc/wcnc2008.html#ZhouJZZ08