Matt W. Mutka Christian Becker Anind K. Dey Francis Lau Gergely V. Záruba 789-790 2008 4 Pervasive and Mobile Computing 6 http://dx.doi.org/10.1016/j.pmcj.2008.09.004 db/journals/percom/percom4.html#MutkaBDLZ08