Nobbs, J., & Hopkins, I. W. J. (1995). Economics: A core text (4th ed.). McGraw-Hill Book Co..

Nobbs, Jack, and I. W. J. Hopkins. Economics: A Core Text. 4th ed. London ; New York: McGraw-Hill Book Co., 1995.

Nobbs, Jack, and I. W. J. Hopkins. Economics: A Core Text. 4th ed. McGraw-Hill Book Co., 1995.