Columbia subject headings:
Coal miners--Labor unions--Spain--Asturias--History--20th century.
Coal miners--Spain--Asturias--History--20th century.
Coal trade--Spain--Asturias--History--20th century.
Strikes and lockouts--Coal mining--Spain--Asturias--History--20th century.
Harvard subject headings:
Coal miners--Labor unions--Spain--Asturias--History--20th century.
Coal miners--Spain--Asturias--History--20th century.
Coal trade--Spain--Asturias--History--20th century.
Strikes and lockouts--Coal mining--Spain--Asturias--History--20th century.
Working class--Spain--History--20th century.
Princeton subject headings:
Coal miners--Labor unions--Spain--Asturias--History--20th century.
Coal miners--Spain--Asturias--History--20th century.
Coal trade--Spain--Asturias--History--20th century.
Strikes and lockouts--Coal mining--Spain--Asturias--History--20th century.