Columbia subject headings:
País Vasco (Spain)--Commerce--History--20th century.
País Vasco (Spain)--Economic conditions.
Harvard subject headings:
País Vasco (Spain)--Commerce--History--20th century.
País Vasco (Spain)--Economic conditions.
Princeton subject headings:
Industries--Spain--País Vasco.
Middle class--Spain--País Vasco--History--20th century.
País Vasco (Spain)--Economic conditions.