APA (7th ed.) Citation

Game Designers' Workshop (Firm). Challenge. Game Designers' Workshop.

Chicago Style (17th ed.) Citation

Game Designers' Workshop (Firm). Challenge. Bloomington, Ill.: Game Designers' Workshop.

MLA (9th ed.) Citation

Game Designers' Workshop (Firm). Challenge. Game Designers' Workshop.

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