@inproceedings{OOPSLA-1989-MadsenM,
	author        = "Ole Lehrmann Madsen and Birger Møller-Pedersen",
	booktitle     = "{Proceedings of the Fourth Conference on Object-Oriented Programming, Systems, Languages and Applications}",
	doi           = "10.1145/74877.74919",
	editor        = "George Bosworth",
	isbn          = "0-89791-333-7",
	pages         = "397--406",
	publisher     = "{ACM}",
	title         = "{Virtual Classes: A Powerful Mechanism in Object-Oriented Programming}",
	year          = 1989,
}