Columbia subject headings:
Harvard subject headings:
Commerce--History--Medieval, 500-1500
Europe--Commerce--History.
Hansa towns--History.
Hanseatic League--History.
Harbors--Germany--Hamburg--History.
Shipping--Germany--Hamburg--History.
Princeton subject headings:
Commerce--History--Medieval, 500-1500.
Europe--Commerce--History.
Hansa towns--History.
Hanseatic League--History.
Harbors--Germany--Hamburg--History.
Shipping--Germany--Hamburg--History.