@conference {1484,
	title = {Proceedings of the 15th International Academic MindTrek Conference: Envisioning Future Media Environments, MindTrek 2011},
	booktitle = {From game design elements to gamefulness: Defining "gamification"},
	year = {2011},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84860665893\&partnerID=MN8TOARS},
	author = {Deterding, S. and Dixon, D. and Khaled, R. and Nacke, L.}
}
