fixing references varie

paper/sections/01-intro.tex

 Global Positioning System (GPS) receivers are well known to be
 power-hungry with respect to the power consumed by a small electronic
-device~\cite{bib:computation-offloading, bib:selective-tracking,
-  bib:microsoft-leap, bib:sparse-fourier, bib:enloc-smartphones,
+device~\cite{
+  bib:microsoft-leap, bib:enloc-smartphones,
   bib:virtualGPS, bib:accuracy-adaptation,
   bib:feasibility-duty-cycling, bib:traffic-delay,
   bib:entracked-datadriven-modeling, bib:senseLess,
-  bib:framework-for-energy-efficiency,
   bib:desing-principles-for-energy-efficiency}. This is probably the
 main reason that motivates research on the optimization of the GPS
 stack and on multi-sensor data merging, for example via sensor
@@ -18,7 +17,8 @@ intertial measurments sensors~\cite{bib:gps-imu}. While the GPS is
 power-hungry but provided very precise information, inertial
 measurments sensors are less demanding in terms of battery, but also
 less precise. In the literature, optimizations of this type are
-accompanied by experimental data~\cite{bib:accuracy-adaptation,
+accompanied by experimental data~\cite{  bib:microsoft-leap, bib:enloc-smartphones,
+  bib:virtualGPS, bib:accuracy-adaptation,
 bib:feasibility-duty-cycling, bib:traffic-delay,
 bib:entracked-datadriven-modeling, bib:senseLess,
 bib:framework-for-energy-efficiency}, that are time-consuming to