APA (7th ed.) Citation

Ruffin & Gregory. (1999). Principles of economics (7th ed.). Addison Wesley.

Chicago Style (17th ed.) Citation

Ruffin and Gregory. Principles of Economics. 7th ed. Boston: Addison Wesley, 1999.

MLA (8th ed.) Citation

Ruffin and Gregory. Principles of Economics. 7th ed. Addison Wesley, 1999.

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