 ~\mbox{%DIFAUXCMD \cite{bcg-ffq-13}\hspace{0pt}%DIFAUXCMD } [ [ \eps\eps .
<meaning-changed>  ~\mbox{%DIFAUXCMD \cite{bcg-ffq-13}\hspace{0pt}%DIFAUXCMD } [ [ \eps\eps .
 ~\mbox{%DIFAUXCMD \cite{bcg-ffq-13}\hspace{0pt}%DIFAUXCMD } [ . We also revisit the time-window data structure for spatial density maps in[ \eps\eps .