एपीए उद्धरण

Heller, R. H. (1977). International trade: Theory and empirical evidence. Prentice Hall of India.

शिकागो स्टाइल उद्धरण

Heller, Robert H. International Trade: Theory and Empirical Evidence. New Delhi: Prentice Hall of India, 1977.

एमएलए उद्धरण

Heller, Robert H. International Trade: Theory and Empirical Evidence. Prentice Hall of India, 1977.