Great Britain & Great Britain. Foreign Office. (1962). Agreement between the Government of the United Kingdom of Great Britain and Northern Ireland and the Government of the Republic of Sudan for air services between and beyond their respective territories: Khartoum, January 16, 1961. H.M.S.O..
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Great Britain و Great Britain. Foreign Office. Agreement Between the Government of the United Kingdom of Great Britain and Northern Ireland and the Government of the Republic of Sudan for Air Services Between and Beyond Their Respective Territories: Khartoum, January 16, 1961. London: H.M.S.O., 1962.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Great Britain و Great Britain. Foreign Office. Agreement Between the Government of the United Kingdom of Great Britain and Northern Ireland and the Government of the Republic of Sudan for Air Services Between and Beyond Their Respective Territories: Khartoum, January 16, 1961. H.M.S.O., 1962.