Columbia subject headings:
Harvard subject headings:
Great Britain--Foreign relations--Portugal.
Liberalism--Portugal--History--19th century.
Portugal--Commercial policy--History--19th century.
Portugal--Foreign relations--Great Britain.
Protectionism--Portugal--History--19th century.
Princeton subject headings:
Great Britain--Foreign economic relations--Portugal.
Liberalism--Portugal.
Portugal--Foreign economic relations--Great Britain.
Portugal--Politics and government--1789-1900.