Cita APA (7th ed.)

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.