Columbia subject headings:
Germany--Foreign relations--United States.
Propaganda, German.
Secret service--Germany.
United States--Foreign relations--Germany.
World War, 1914-1918.
Harvard subject headings:
Germany--Foreign relations--United States.
Propaganda, German.
Secret service--Germany
United States--Foreign relations--Germany.
World War, 1914-1918
Princeton subject headings:
Germany--Foreign relations--United States.
Propaganda, German.
Secret service--Germany.
United States--Foreign relations--Germany.
World War, 1914-1918.