Bader. (1970). The Integration of The State Insurance Into The Economic System of The German Democratic Republic. The Institute of National Planning.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Bader. The Integration of The State Insurance Into The Economic System of The German Democratic Republic. Cairo: The Institute of National Planning, 1970.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Bader. The Integration of The State Insurance Into The Economic System of The German Democratic Republic. The Institute of National Planning, 1970.