Maria Francesca Costabile Antonella De Angeli Rosa Lanzilotti Carmelo Ardito Paolo Buono Thomas Pederson Explore! possibilities and challenges of mobile learning. 145-154 2008 CHI http://doi.acm.org/10.1145/1357054.1357080 conf/chi/2008 db/conf/chi/chi2008.html#CostabileALABP08