Columbia subject headings:
Harvard subject headings:
B. Simons & Co.--Biography.
Bankers--Germany--Biography
Leiffmann, Moritz, 1853-1921.
Poensgen, Kurt, 1885-1944.
Simons, Michael, 1817-1895.
Princeton subject headings:
B. Simons & Co.--History.
Bankers--Germany--Biography.
Banks and banking--Germany--Düsseldorf--History.
Simons, Michael, 1817-1895.