Quote
S. Gansemer, S. Hakobyan, and S. Pueschel, "3D WIFI indoor positioning in multi-storey buildings," in 2009 IEEE international workshop on intelligent data acquisition and advanced computing systems : technology and applications ; Rende, Cosenza, Italy, September 21-23, 2009, Piscataway, NJ: IEEE, 2009, pp. 353-656.