Columbia subject headings:
Harvard subject headings:
Ochel, Ewald, 1875-1957
Revolutionaries--Germany--Düsseldorf--Biography.
Revolutions--Germany--Düsseldorf--History--20th century--Sources.
Socialists--Germany--Düsseldorf--Biography.
Princeton subject headings:
Ochel, Ewald, 1875-1957.
Revolutionaries--Germany--Düsseldorf--Biography.
Revolutions--Germany--Düsseldorf--History--20th century--Sources.
Socialists--Germany--Düsseldorf--Biography.