Electricity supply, 1930-31 : return of engineering and financial statistics relating to authorised undertakings in Great Britain for the year ending March 31, 1931 (or May 15, 1931) for public authority undertakings, and December 31, 1930, for company undertakings /
Great Britain.Electricity Commission,issuing body.
Great Britain.His Majesty's Stationery Office.
Great Britain.Ministry of Transport.