Doug Vogel David M. Kennedy Kevin Kuan Ron Chi-Wai Kwok Jean Lai Do Mobile Device Applications Affect Learning? 4 2007 conf/hicss/2007 HICSS http://doi.ieeecomputersociety.org/10.1109/HICSS.2007.181 db/conf/hicss/hicss2007.html#VogelKKKL07