Columbia subject headings:
Maritime law--Germany--History--21st century.
Maritime terrorism--Germany--Prevention--History--21st century.
Piracy--Germany--Prevention--History--21st century.
Shipping--Germany--History--21st century.
Harvard subject headings:
Maritime law--Germany--History--21st century.
Maritime terrorism--Germany--Prevention--History--21st century.
Piracy--Germany--Prevention--History--21st century.
Shipping--Germany--History--21st century.
Princeton subject headings: