Tohutoro APA (7th ed.)

Heller, H. R. (1968). International trade theory and empirical evidence. Prentic- Hall.

Tohutoru Kātū Chicago (17th ed.)

Heller, H. Robert. International Trade Theory and Empirical Evidence. NewJersey: Prentic- Hall, 1968.

Tohutoro MLA (9th ed.)

Heller, H. Robert. International Trade Theory and Empirical Evidence. Prentic- Hall, 1968.