Columbia subject headings:
Latin America--Economic conditions--Congresses.
Spain--Commerce--History--Congresses.
Spain--Economic conditions--Congresses.
Harvard subject headings:
Harbors--Spain--History--18th century.
País Vasco (Spain)--Commerce.
País Vasco (Spain)--Economic conditions.
Princeton subject headings:
Harbors--Spain--History--18th century--Congresses.
País Vasco (Spain)--Commerce--Congresses.
País Vasco (Spain)--Economic conditions--Congresses.