APA Citation

Koster, R. (2013). A theory of fun for game design (2nd edition.). Sebastopol, CA: O'Reilly.

Chicago Style Citation

Koster, Raph. A Theory of Fun for Game Design. 2nd edition. Sebastopol, CA: O'Reilly, 2013.

MLA Citation

Koster, Raph. A Theory of Fun for Game Design. 2nd edition. Sebastopol, CA: O'Reilly, 2013.

Warning: These citations may not always be 100% accurate.