@article {CaLe2011,
	title = {Unifying Class-Based Representation Formalisms},
	journal = {JOURNAL OF ARTIFICIAL INTELLIGENCE},
	volume = {11},
	year = {2011},
	pages = {199{\textendash}240},
	publisher = {Journal of Artificial Intelligence Research},
	doi = {10.1613/jair.548},
	author = {Calvanese, D. and Lenzerini, M. and D. Nardi}
}
