CastronovaE. (2005). Synthetic worlds: The business and culture of online games. Chicago, IL: University of Chicago Press.
2.
CastronovaE. (2007). Exodus to the virtual world. Basingstoke, England: Palgrave Macmillan.
3.
DeciE. L.KoestnerR.RyanR. M. (1999). A meta-analytic review of experiments examining the effects of extrinsic rewards on intrinsic motivation. Psychological Bulletin, 125, 627–668.
4.
HuizingaJ. (1955). Homo ludens: A study of the play-element in culture. Boston, MA: Beacon Press.
5.
McGonigalJ. (2011). Reality is broken: Why games make us better and how they can change the world. New York, NY: Penguin Press.
