APA (7th ed.) Citation
Helpman, E., & Krugman, P. R. (1993). Market Structure and Foreign Trade: Increasing Returns, Imperfect Competition, and the International Economy (5. ed.). MIT Press.
Chicago Style (17th ed.) Citation
Helpman, Elhanan, and Paul R. Krugman. Market Structure and Foreign Trade: Increasing Returns, Imperfect Competition, and the International Economy. 5. ed. Cambridge: MIT Press, 1993.
MLA (9th ed.) Citation
Helpman, Elhanan, and Paul R. Krugman. Market Structure and Foreign Trade: Increasing Returns, Imperfect Competition, and the International Economy. 5. ed. MIT Press, 1993.
Warning: These citations may not always be 100% accurate.