Columbia subject headings:
Germany--Foreign relations--1888-1918.
World War, 1914-1918--Germany--Communications.
World War, 1914-1918--Sources.
Harvard subject headings:
World War, 1914-1918--Documents, etc., sources--Periodicals.
World War, 1914-1918--Periodicals
Princeton subject headings:
Germany--Foreign relations--1888-1918.
World War, 1914-1918--Germany--Communications.
World War, 1914-1918--Sources.