APA (7th ed.) Citation

Koster, R. (2005). A theory of fun for game design. Paraglyph Press.

Chicago Style (17th ed.) Citation

Koster, Raph. A Theory of Fun for Game Design. Scottsdale, AZ: Paraglyph Press, 2005.

MLA (8th ed.) Citation

Koster, Raph. A Theory of Fun for Game Design. Paraglyph Press, 2005.

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