Columbia subject headings:
Social classes--Spain--Vizcaya--History--18th century.
Vizcaya (Spain)--History--18th century.
Vizcaya (Spain)--Social conditions--18th century.
Harvard subject headings:
Social classes--Spain--Vizcaya--History--18th century.
Vizcaya (Spain)--History--18th century.
Vizcaya (Spain)--Social conditions--18th century.
Princeton subject headings:
Social classes--Spain--Vizcaya--History--18th century.
Vizcaya (Spain)--History--18th century.
Vizcaya (Spain)--Social conditions--18th century.