Heller, H. R. (1973). International trade: Theory and empirical evidence (2nd ed.). Prentice-Hall of India.
शिकागो स्टाइल उद्धरणHeller, H. Robert. International Trade: Theory and Empirical Evidence. 2nd ed. New Jersey: Prentice-Hall of India, 1973.
एमएलए उद्धरणHeller, H. Robert. International Trade: Theory and Empirical Evidence. 2nd ed. Prentice-Hall of India, 1973.
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