RCC7787  Secret Service  (Aston)

RCC6981  British Secret Service During the Great War  (Everitt)

RCC7485  Inside Room 40: The Codebreakers of World War 1  (Gannon)

RCC7660  Alastair Denniston. Code Breaking from Room 40 to Berkeley Street and the Birth of GCHQ  (Greenberg)

RCC5918  Armour Against Fate: British Military Intelligence in the First World War: And The Secret Rescue From Russia of the Grand Duchess Tatiana  (Occleshaw)

RCC6292  Agents of Empire: Anglo-Zionist Intelligence Operations 1915 - 1919: Brigadier Walter Gribbon, Aaron Aaronsohn and the NILI Ring  (Verrier)

RCC5919  The Secrets of Rue St. Roch: Intelligence Operations Behind Enemy Lines in the First World War  (Morgan)