McConnell, C. R. (1981). Economics: Principles, problems, and policies (10th ed.). McGraw-Hill.

McConnell, Campbell R. Economics: Principles, Problems, and Policies. 10th ed. New York: McGraw-Hill, 1981.

McConnell, Campbell R. Economics: Principles, Problems, and Policies. 10th ed. McGraw-Hill, 1981.