Hi Jocelyn (et al),
Ref: Sharples et al 2007 - Google turned up 130,000 hits, of which presumably 129,000+ would be irrelevant. However there are potentially useful references in the M-Learning conference call for papers (
http://www.mlearning-conf.org/cfp.asp), and a possible contact at Birmingham University, viz: Susan Bull (
http://www.eee.bham.ac.uk/bull/) who may be able to give more direct clarification. HTH