Columbia subject headings:
Harvard subject headings:
Guadiana River (Spain and Portugal)--Social conditions.
Millers--Guadiana River (Spain and Portugal)
Mills and mill-work--Guadiana River (Spain and Portugal)
Princeton subject headings:
Guadiana River (Spain and Portugal)--Social conditions.
Millers--Guadiana River (Spain and Portugal).
Mills and mill-work--Guadiana River (Spain and Portugal).