@booklet {TR-10-2001,
	title = {A Unifying Semantic Framework for Multilevel Metamodelling},
	year = {2001},
	month = {October},
	publisher = {Budapest University of Technology and Economics},
	url = {http://www.inf.mit.bme.hu/FTSRG/Publications/varro/2001/metamodelling.ps},
	author = {D{\'a}niel Varr{\'o} and Andr{\'a}s Pataricza}
}
