@article {JVC,
	title = {Defining Visual Notations and Their Manipulation through Meta-Modelling and Graph Transformation},
	journal = {Journal of Visual Languages and Computing},
	volume = {15},
	number = {3 - 4},
	year = {2004},
	note = {Special Issue on Domain-Specific Modeling with Visual Languages},
	month = {June - August},
	pages = {309{\textendash}330},
	publisher = {Elsevier}
}
