Ghadi, Y. (1989). The development of the financial system in the early Islamic State ('Umar's Reign 13 - 23 A. H /624-634 A.D.) with special reference to the problem of poverty and some aspects of the practice. University of London.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Ghadi, Yasin. The Development of the Financial System in the Early Islamic State ('Umar's Reign 13 - 23 A. H /624-634 A.D.) with Special Reference to the Problem of Poverty and Some Aspects of the Practice. London, England: University of London, 1989.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Ghadi, Yasin. The Development of the Financial System in the Early Islamic State ('Umar's Reign 13 - 23 A. H /624-634 A.D.) with Special Reference to the Problem of Poverty and Some Aspects of the Practice. University of London, 1989.