APA (7th ed.) Citation

Grotewold, A. (1979). The regional theory of world trade. Ptolemy Press.

Chicago Style (17th ed.) Citation

Grotewold, Andreas. The Regional Theory of World Trade. Grove City, Pa.: Ptolemy Press, 1979.

MLA (9th ed.) Citation

Grotewold, Andreas. The Regional Theory of World Trade. Ptolemy Press, 1979.

Warning: These citations may not always be 100% accurate.