Columbia subject headings:
Harvard subject headings:
Europe, Northern--Foreign relations--United States.
Intelligence service--United States--History--20th century
United States--Foreign relations--Europe, Northern.
United States. Central Intelligence Agency. Office of Support Services.
United States. Office of Strategic Services.
World War, 1939-1945--Secret service--United States.
Princeton subject headings:
Europe, Northern--Foreign relations--United States.
Intelligence service--United States--History--20th century.
United States--Foreign relations--Europe, Northern.
United States. Office of Strategic Services
World War, 1939-1945--Secret service--United States.