@inproceedings{DiGRA-2007-Juul,
	author        = "Jesper Juul",
	booktitle     = "{Proceedings of the Fourth DiGRA International Conference: Situated Play}",
	ee            = "http://www.digra.org/digital-library/publications/a-certain-level-of-abstraction/",
	publisher     = "{Digital Games Research Association}",
	title         = "{A Certain Level of Abstraction}",
	year          = 2007,
}