@inproceedings{UML-2001-AtkinsonK,
	author        = "Colin Atkinson and Thomas Kühne",
	booktitle     = "{Proceedings of the Fourth International Conference on the Unified Modeling Language, Modeling Languages, Concepts, and Tools}",
	doi           = "10.1007/3-540-45441-1_3",
	editor        = "Martin Gogolla and Cris Kobryn",
	isbn          = "3-540-42667-1",
	pages         = "19--33",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{The Essence of Multilevel Metamodeling}",
	volume        = 2185,
	year          = 2001,
}