Yelena Nakhimovsky Dean Eckles Jens Riegelsberger Mobile user experience research: challenges, methods & tools. 4795-4798 2009 CHI Extended Abstracts http://doi.acm.org/10.1145/1520340.1520743 conf/chi/2009a db/conf/chi/chi2009a.html#NakhimovskyER09a