APA (7th ed.) Citation

" Singh, S. The code book: The secret history of codes and code-breaking. Forth Estate Ltd.

Chicago Style (17th ed.) Citation

" Singh, Simon". The Code Book: The Secret History of Codes and Code-breaking. Forth Estate Ltd.

MLA (9th ed.) Citation

" Singh, Simon". The Code Book: The Secret History of Codes and Code-breaking. Forth Estate Ltd.

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