Columbia subject headings:
Bonn (Germany)--History--20th century.
World War, 1914-1918--Germany--Bonn.
Harvard subject headings:
Bonn (Germany)--History--20th century.
World War, 1914-1918--Germany--Bonn.
Princeton subject headings:
Bonn (Germany)--History--20th century.
World War, 1914-1918--Germany--Bonn.