Columbia subject headings:
Harvard subject headings:
Ashio-machi Region (Japan)--Social conditions.
Copper industry and trade--Environmental aspects--Japan--Ashio-machi Region--History.
Copper miners--Japan--Ashio-machi Region--History.
Strikes and lockouts--Copper mining--Japan--Ashio-machi Region--History.
Princeton subject headings:
Ashio-machi Region (Japan)--Social conditions.
Copper industry and trade--Environmental aspects--Japan--Ashio-machi Region--History.
Copper miners--Japan--Ashio-machi Region--History.
Strikes and lockouts--Copper mining--Japan--Ashio-machi Region--History.