horn, k. h. (1967). structural changes and productivity. the institute of national planning.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিhorn, karl heinz. Structural Changes and Productivity. cairo: the institute of national planning, 1967.
M.L.A (9 ম সংস্করণ) উদ্ধৃতিhorn, karl heinz. Structural Changes and Productivity. the institute of national planning, 1967.