Columbia subject headings:
Commercial policy--History--19th century.
Commercial policy--History--20th century.
International economic relations--History--19th century.
International economic relations--History--20th century.
Harvard subject headings:
Commercial policy--History--19th century.
Commercial policy--History--20th century.
International economic relations--History--19th century.
International economic relations--History--20th century
Princeton subject headings:
Commercial policy--History--19th century.
Commercial policy--History--20th century.
International economic relations--History--19th century.
International economic relations--History--20th century.