Bingham, R. C., & Pope, W. H. (1993). Economic concepts: A programmed approach (10th ed. / revised by William Henry Pope.). McGraw-Hill.

Bingham, Robert C., and W. H. Pope. Economic Concepts: A Programmed Approach. 10th ed. / revised by William Henry Pope. New York: McGraw-Hill, 1993.

Bingham, Robert C., and W. H. Pope. Economic Concepts: A Programmed Approach. 10th ed. / revised by William Henry Pope. McGraw-Hill, 1993.