horn, k. h. (1967). structural changes and productivity. the institute of national planning.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रhorn, karl heinz. Structural Changes and Productivity. cairo: the institute of national planning, 1967.
एमएलए (9वां संस्करण) प्रशस्ति पत्रhorn, karl heinz. Structural Changes and Productivity. the institute of national planning, 1967.