Coal output (monthly statistics). Return (in part) to an order of the Honourable the House of Commons, dated 8 March 1921;--for, return "relating to the output of coal at coal mines in the United Kingdom during periods of four weeks, commencing with the period ended the 21st day of June 1919, and to the number of workpeople employed at the end of those periods, in the various districts. (In continuation of Parliamentary Paper no. 33 of session 1920.) [electronic resource].