Columbia subject headings:
Harvard subject headings:
Copper mines and mining--Spain--Tinto River Region--History--20th century.
Miners--Spain--Tinto River Region--Social conditions--20th century.
Rio Tinto Company--History.
Princeton subject headings:
British--Spain--Minas de Ríotinto--History--20th century.
Labor unions--Press coverage--Spain--Minas de Ríotinto--History--20th century.
Mineral industries--Spain--Minas de Ríotinto--History.
Miners--Spain--Minas de Ríotinto--History--20th century.
Press, Labor--Spain--Minas de Ríotinto--History--20th century.
Rio Tinto Company--Press coverage--History--20th century.