Columbia subject headings:
Harvard subject headings:
Baltic Sea Region--Commerce--History.
Commerce--History--16th century.
Commerce--History--Medieval, 500-1500
Hansa towns--History.
Hanseatic League--History.
North Sea Region--Commerce--History.
Princeton subject headings:
Baltic Sea Region--History.
Europe, Northern--History.
Hansa towns--History.
Hanseatic League--History.
North Sea region--History.