@conference {simidat222,
	title = {Subgroup discovery in an e-learning usage study based on Moodle},
	booktitle = {International Conference on EUropean Transnational Education (ICEUTE)},
	year = {2011},
	note = {TIN-2008-06681-C06-02,TIN-2008-06681-C06-03,TIC-3928,TIC-3720},
	month = {October},
	pages = {26-31},
	address = {Salamanca (Spain)},
	author = {C. J. Carmona and P. Gonz{\'a}lez and M. J. del Jesus and S. Ventura}
}
