| Subject | Industrial relations--Wales, South; Management--Employee representation; Coal mines and mining--Collective labour bargaining; Firedamp--Wales, South; Coal trade--Fires and fire prevention--Wales, South; Mine examination--Wales, South; Mine safety--Wales, South; Coal mines and mining--Safety regulations--Wales, South; Coal miners--Trades unions--Wales, South; Trades unions--Records and correspondence; Trades union branches--Wales, South; Wages--Coal miners; Price indexes; Trades unions--Accounting; Mine maps; Coal mines and mining--Safety measures; |