Bingham, R. C., & Pope, W. H. (1993). Economic concepts: A programmed approach (10th ed. / revised by William Henry Pope.). McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Bingham, Robert C., agus W. H. Pope. Economic Concepts: A Programmed Approach. 10th ed. / revised by William Henry Pope. New York: McGraw-Hill, 1993.
Lua MLA (8ú heag.)Bingham, Robert C., agus W. H. Pope. Economic Concepts: A Programmed Approach. 10th ed. / revised by William Henry Pope. McGraw-Hill, 1993.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.