@book{164527,
	author = {Koster, Raph,},
	title = {A theory of fun for game design /},
	publisher = {O'Reilly,},
	year = {2013.},
	address = {Sebastopol, CA :},
	edition = {2nd edition.},
	note = {Previous edition: Scottsdale, Arizona: Paraglyph, 2005.}
}