Não informado. (2021). Annual Bulletin of Coal Statistics for Europe and North America. United Nations.
Style de citation Chicago (17e éd.)Não informado. Annual Bulletin of Coal Statistics for Europe and North America. New York: United Nations, 2021.
Style de citation MLA (8e éd.)Não informado. Annual Bulletin of Coal Statistics for Europe and North America. United Nations, 2021.
Attention : ces citations peuvent ne pas être correctes à 100%.