Cita APA (7a ed.)

Ferris, J. (2021). Behind the enigma: The authorised history of GCHQ, Britain´s Secret Cyber-Intelligence Agency. Bloomsbury Publishing.

Cita Chicago Style (17a ed.)

Ferris, John. Behind the Enigma: The Authorised History of GCHQ, Britain´s Secret Cyber-Intelligence Agency. London Oxford New York New Delhi Sydney: Bloomsbury Publishing, 2021.

Cita MLA (9a ed.)

Ferris, John. Behind the Enigma: The Authorised History of GCHQ, Britain´s Secret Cyber-Intelligence Agency. Bloomsbury Publishing, 2021.