Columbia subject headings:
Espionage, German--Turkey.
Germany--Foreign relations--Turkey.
Military intelligence--Germany--History.
Secret service--Germany--History.
Spies--Germany.
Turkey--Foreign relations--Germany.
Harvard subject headings:
Espionage, German--Turkey.
Germany--Foreign relations--Turkey.
Military intelligence--Germany--History.
Secret service--Germany--History.
Spies--Germany.
Turkey--Foreign relations--Germany.
Princeton subject headings:
Espionage, German--Turkey.
Germany--Foreign relations--Turkey.
Military intelligence--Germany--History.
Secret service--Germany--History.
Spies--Germany.
Turkey--Foreign relations--Germany.