Bingham, R. C. (1981). Economic concepts: A programmed approach (6th ed.). McGraw-Hill.
Chicago-čujuhus (17. p.)Bingham, Robert C. Economic Concepts: A Programmed Approach. 6th ed. New York: McGraw-Hill, 1981.
MLA-čujuhus (9. p.)Bingham, Robert C. Economic Concepts: A Programmed Approach. 6th ed. McGraw-Hill, 1981.
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