APA (7th ed.) Citation

Krugman, P. R., Obstfeld, M., & Melitz, M. J. (2012). International economics: Theory and policy (9th ed.). Addison-Wesley.

Chicago Style (17th ed.) Citation

Krugman, Paul R., Maurice Obstfeld, and Marc J. Melitz. International Economics: Theory and Policy. 9th ed. Boston: Addison-Wesley, 2012.

MLA (8th ed.) Citation

Krugman, Paul R., et al. International Economics: Theory and Policy. 9th ed. Addison-Wesley, 2012.