APA (7th ed.) Citation

Krugman, P. R., & Wells, R. (2009). Economics (2. ed., 3. print.). Worth.

Chicago Style (17th ed.) Citation

Krugman, Paul R., and Robin Wells. Economics. 2. ed., 3. print. New York, NY: Worth, 2009.

MLA (9th ed.) Citation

Krugman, Paul R., and Robin Wells. Economics. 2. ed., 3. print. Worth, 2009.