Não informado. (1956). Half-yearly Bulletin of Electric Energy Statistics for Europe. United Nations, Economic Commission for Europe.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Não informado. Half-yearly Bulletin of Electric Energy Statistics for Europe. New York: United Nations, Economic Commission for Europe, 1956.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Não informado. Half-yearly Bulletin of Electric Energy Statistics for Europe. United Nations, Economic Commission for Europe, 1956.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.