Não informado. (1956). Half-yearly Bulletin of Electric Energy Statistics for Europe. United Nations, Economic Commission for Europe.
Citação do estilo Chicago (17ª ed.)Não informado. Half-yearly Bulletin of Electric Energy Statistics for Europe. New York: United Nations, Economic Commission for Europe, 1956.
Citação MLA (8ª ed.)Não informado. Half-yearly Bulletin of Electric Energy Statistics for Europe. United Nations, Economic Commission for Europe, 1956.
警告：這些引文格式不一定是100％准確.