@book{40024,
	author = {Klabbers, Jan H.G.,},
	title = {The Magic Circle: Principles of Gaming & Simulation :},
	publisher = {Brill | Sense,},
	year = {2009.},
	series = {Modeling and Simulation for Learning and Instruction ;},
	address = {Leiden; },
	url = {http://dx.doi.org/10.1163/9789087903107}
}