APA (7th ed.) Citation

Grant, H. Spies and Secret Service The story of espionage, its main systems and chief exponents.

Chicago Style (17th ed.) Citation

Grant, Hamil. Spies and Secret Service The Story of Espionage, Its Main Systems and Chief Exponents.

MLA (9th ed.) Citation

Grant, Hamil. Spies and Secret Service The Story of Espionage, Its Main Systems and Chief Exponents.

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