linsel, h., & sach, k. (1965). practical problems of investment: Planning and financing. National Planning Institute.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)linsel, hermann, و kurt sach. Practical Problems of Investment: Planning and Financing. cairo: National Planning Institute, 1965.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)linsel, hermann, و kurt sach. Practical Problems of Investment: Planning and Financing. National Planning Institute, 1965.