APA (7th ed.) Citation

Krugman, P. R., & Obstfeld, M. nternational economics: Theory and policy (Ninth edition.).

Chicago Style (17th ed.) Citation

Krugman, Paul R., and Maurice Obstfeld. Nternational Economics: Theory and Policy. Ninth edition.

MLA (9th ed.) Citation

Krugman, Paul R., and Maurice Obstfeld. Nternational Economics: Theory and Policy. Ninth edition.

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