Columbia subject headings:
Harvard subject headings:
Harbors--Germany, Northern--Traffic control--History--Catalogs.
Harbors--Germany--Bremen--Traffic control--History--Catalogs.
North Sea Coast (Germany)--Commerce--History--16th century--Sources--Bibliography--Catalogs.
North Sea Coast (Germany)--Commerce--History--17th century--16th century--Sources--Bibliography--Catalogs.
North Sea Coast (Germany)--Commerce--History--18th century--16th century--Sources--Bibliography--Catalogs.
North Sea Coast (Germany)--Commerce--History--19th century--16th century--Sources--Bibliography--Catalogs.
Shipping--Germany, Northern--History--Catalogs.
Shipping--Germany--North Sea Coast--History--Sources--Bibliography--Catalogs.
Shipping--North Sea--History--Catalogs.
Princeton subject headings:
Catalogs.
North Sea Coast (Germany)--Commerce--History--16th century--Sources--Bibliography--Catalogs.
North Sea Coast (Germany)--Commerce--History--17th century--16th century--Sources--Bibliography--Catalogs.
North Sea Coast (Germany)--Commerce--History--18th century--16th century--Sources--Bibliography--Catalogs.
North Sea Coast (Germany)--Commerce--History--19th century--16th century--Sources--Bibliography--Catalogs.
Shipping--North Sea Coast (Germany)--History--Sources--Bibliography--Catalogs.