1. R. Want, A. Hopper, V. Falcao, J. Gibbons, The active badge location system, ACM Trans. Inf. Syst. 10 (1) (1992) 91-102. doi:http: //doi.acm.org/10.1145/128756.128759.
2. P. Bahl, V.N. Padmanabhan, RADAR: An in-building RF-based user location and tracking system, in: INFOCOM, 2000, pp. 775-784. URL http://www.ieee-infocom.org/2000/papers/589.pdf.
3. K. Kaemarungsi, P. Krishnamurthy, Properties of indoor received signal strength for WLAN location fingerprinting, in: Proc. MobiQuitous’ 04, 2004, pp. 14-23.URL http://csdl.computer.org/comp/proceedings/mobiquitous/2004/2208/00/22080014abs.htm.
4. A new location technique for the active office;Ward;IEEE Pers. Comm.,1997
5. N. Priyantha, A. Chakraborty, H. Balakrishnan, The cricket location support system, in: Proc. Mobicom’00, 2000.