Columbia subject headings:
Harvard subject headings:
Great Britain--Foreign economic relations--Portugal.
Pombal, Sebastião José de Carvalho e Melo, Marquês de, 1699-1782.
Port wine--Portugal--History--18th century.
Portugal--Dependency on Great Britain--History--18th century.
Portugal--Foreign economic relations--Great Britain.
Wine industry--Portugal--History--18th century.
Princeton subject headings:
Pombal, Sebastião José de Carvalho e Melo, Marquês de, 1699-1782.
Port wine--History.
Viticulture--Portugal--History.
Wine and wine making--Portugal--Porto--History.