Heller, H. R. (1973). International trade: Theory and empirical evidence (2d ed.). Prentice-Hall.
Čikaški stil citiranja (17. izdanje)Heller, H. Robert. International Trade: Theory and Empirical Evidence. 2d ed. Englewood Cliffs, N.J.: Prentice-Hall, 1973.
MLA način citiranja (8. izdanje)Heller, H. Robert. International Trade: Theory and Empirical Evidence. 2d ed. Prentice-Hall, 1973.
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