Columbia subject headings:
Intelligence service--Great Britain--History--20th century.
Harvard subject headings:
Civil rights--Great Britain
Great Britain. MI5--History.
Intelligence service--Great Britain--History--20th century.
Internal security--Great Britain--History--20th century.
Saravanos, Basil.
Princeton subject headings:
Civil rights--Great Britain.
Great Britain. MI5
Internal security--Great Britain.
Saravanos, Basil.