APA (7th ed.) Citation

Zichermann, G., & Cunningham, C. (2011). Gamification by design: Implementing game mechanics in web and mobile apps. O'Reilly.

Chicago Style (17th ed.) Citation

Zichermann, Gabe, and Christopher Cunningham. Gamification by Design: Implementing Game Mechanics in Web and Mobile Apps. Sebastopol: O'Reilly, 2011.

MLA (9th ed.) Citation

Zichermann, Gabe, and Christopher Cunningham. Gamification by Design: Implementing Game Mechanics in Web and Mobile Apps. O'Reilly, 2011.