APA (7th ed.) Citation

Great Britain. Foreign Office & National Archives (Great Britain). (2006). Political Departments, general correspondence from 1906-1966. National Archives.

Chicago Style (17th ed.) Citation

Great Britain. Foreign Office and National Archives (Great Britain). Political Departments, General Correspondence from 1906-1966. [London]: National Archives, 2006.

MLA (8th ed.) Citation

Great Britain. Foreign Office and National Archives (Great Britain). Political Departments, General Correspondence from 1906-1966. National Archives, 2006.