Não informado. (1968). Annual Bulletin of Coal Statistics for Europe. United Nations, Economic Commission for Europe.
Citace podle Chicago (17th ed.)Não informado. Annual Bulletin of Coal Statistics for Europe. New York: United Nations, Economic Commission for Europe, 1968.
Citace podle MLA (8th ed.)Não informado. Annual Bulletin of Coal Statistics for Europe. United Nations, Economic Commission for Europe, 1968.
Upozornění: Tyto citace jsou generovány automaticky. Nemusí být zcela správně podle citačních pravidel..