Não informado. (1974). Coal and Energy Quarterly. National Coal Board.
Citace podle Chicago (17th ed.)Não informado. Coal and Energy Quarterly. London: National Coal Board, 1974.
Citace podle MLA (8th ed.)Não informado. Coal and Energy Quarterly. National Coal Board, 1974.
Upozornění: Tyto citace jsou generovány automaticky. Nemusí být zcela správně podle citačních pravidel..