@inproceedings{UML-1997-Frank,
	author        = "Ulrich Frank",
	booktitle     = "{The Unified Modeling Language — Technical Aspects and Applications}",
	isbn          = "3-7908-1105-X",
	pages         = "14--31",
	publisher     = "{Physica-Verlag}",
	title         = "{Object-Oriented Modeling Languages: State of the Art and Open Research Questions}",
	year          = 1997,
}