Knauthe, H. E. (1966). Prospective Planning and Investment Decisions: Economic Problems Concerned with Preparation and Carrying out of Investments. The institute of national planning.
Lua i Stíl Chicago (17ú heag.)Knauthe, Habil Erhart. Prospective Planning and Investment Decisions: Economic Problems Concerned with Preparation and Carrying Out of Investments. Cairo: The institute of national planning, 1966.
Lua MLA (9ú heag.)Knauthe, Habil Erhart. Prospective Planning and Investment Decisions: Economic Problems Concerned with Preparation and Carrying Out of Investments. The institute of national planning, 1966.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.