Columbia subject headings:
Coal miners--Political activity--England--Yorkshire--History.
Labor unions--Political activity--England--Yorkshire--History.
Labour Party (Great Britain)--History--20th century.
National Union of Mineworkers--History.
Harvard subject headings:
Coal miners--England--Yorkshire--Political activity--History.
Labor unions--England--Yorkshire--Political activity--History.
Labour Party (Great Britain)--History--20th century.
National Union of Mineworkers--History.
Princeton subject headings:
Labor unions--England--Yorkshire--Political activity--History--20th century.
National Union of Mineworkers. Yorkshire Area--History--20th century.