Brecht Desmet Kristof Vanhaesebrouck Jorge Vallejos Pascal Costanza Wolfgang De Meuter The Puzzle Approach for Designing Context-Enabled Applications. 23-29 2007 conf/sccc/2007 SCCC http://doi.ieeecomputersociety.org/10.1109/SCCC.2007.18 db/conf/sccc/sccc2007.html#DesmetVVCM07