Heller, H. R. (1973). International trade: Theory and empirical evidence (2d ed.). Prentice-Hall.
Cita Chicago (17th ed.)Heller, H. Robert. International Trade: Theory and Empirical Evidence. 2d ed. Englewood Cliffs, N.J.: Prentice-Hall, 1973.
Cita MLA (8th ed.)Heller, H. Robert. International Trade: Theory and Empirical Evidence. 2d ed. Prentice-Hall, 1973.
Atenció: Aquestes cites poden no estar 100% correctes.