APA (7th ed.) Citation

Ferris, J. (2020). Behind the enigma: The authorised history of GCHQ, Britain's secret cyber-intelligence agency. Bloomsbury Publishing.

Chicago Style (17th ed.) Citation

Ferris, John. Behind the Enigma: The Authorised History of GCHQ, Britain's Secret Cyber-intelligence Agency. New York: Bloomsbury Publishing, 2020.

MLA (9th ed.) Citation

Ferris, John. Behind the Enigma: The Authorised History of GCHQ, Britain's Secret Cyber-intelligence Agency. Bloomsbury Publishing, 2020.

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