Columbia subject headings:
Harvard subject headings:
Miners--Germany--Ruhr (Region)--History.
Miners--Germany--Ruhr (Region)--Interviews.
Older people--Germany--Ruhr (Region)--History.
Oral biography.
Ruhr (Germany : Region)--Biography.
Ruhr (Germany : Region)--Economic conditions
Princeton subject headings:
Oral history.
Ruhr (Germany : Region)--History.