linsel, h., & sack, k. (1965). theoretical problems of investment planning. National Planning Institute.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিlinsel, hermann, এবং kurt sack. Theoretical Problems of Investment Planning. cairo: National Planning Institute, 1965.
M.L.A (9 ম সংস্করণ) উদ্ধৃতিlinsel, hermann, এবং kurt sack. Theoretical Problems of Investment Planning. National Planning Institute, 1965.