Columbia subject headings:
Coal miners--Great Britain.
Coal miners.
Coal mines and mining--Government ownership--Great Britain.
Coal trade--Great Britain.
Mines and mineral resources--Government ownership.
World War, 1914-1918--Economic aspects--Great Britain.
Harvard subject headings:
Coal miners--Great Britain
Coal trade--Great Britain
Mines and mineral resources--Government ownership
World War, 1914-1918--Economic aspects--Great Britain
Princeton subject headings:
Coal miners--Great Britain.
Coal trade--Great Britain.
Mines and mineral resources--Government ownership.
World War, 1914-1918--Economic aspects--Great Britain.