Susana Alcalde Bagüés Andreas Zeidler Carlos Fernandez Valdivielso Ignacio R. Matias Disappearing for a while - using <i>white lies</i> in pervasive computing. 80-83 2007 WPES http://doi.acm.org/10.1145/1314333.1314349 conf/wpes/2007 db/conf/wpes/wpes2007.html#BaguesZVM07