Alex Varshavsky Denis Pankratov John Krumm Eyal de Lara Calibree: Calibration-Free Localization Using Relative Distance Estimations. 146-161 2008 Pervasive http://dx.doi.org/10.1007/978-3-540-79576-6_9 conf/pervasive/2008 db/conf/pervasive/pervasive2008.html#VarshavskyPKL08