APA (7th ed.) Citation

Kagan, N., & Hyslop, S. G. (2016). The secret history of World War II: Spies, code breakers & covert operations. National Geographic.

Chicago Style (17th ed.) Citation

Kagan, Neil, and Stephen G. Hyslop. The Secret History of World War II: Spies, Code Breakers & Covert Operations. Washington, D.C.: National Geographic, 2016.

MLA (9th ed.) Citation

Kagan, Neil, and Stephen G. Hyslop. The Secret History of World War II: Spies, Code Breakers & Covert Operations. National Geographic, 2016.