APA (7th ed.) Citation

Walters, D. (2020). The history of the British 'U' class submarine. Pen & Sword Maritime.

Chicago Style (17th ed.) Citation

Walters, Derek. The History of the British 'U' Class Submarine. Barnsley, South Yorkshire, UK: Pen & Sword Maritime, 2020.

MLA (9th ed.) Citation

Walters, Derek. The History of the British 'U' Class Submarine. Pen & Sword Maritime, 2020.