APA (7th ed.) Citation

Ruffin, R., & Gregory, P. R. (1992). Principles of economics (5th edition.). Harper Collin College Publishers.

Chicago Style (17th ed.) Citation

Ruffin, Roy, and Paul R. Gregory. Principles of Economics. 5th edition. Principles of economics: Harper Collin College Publishers, 1992.

MLA (8th ed.) Citation

Ruffin, Roy, and Paul R. Gregory. Principles of Economics. 5th edition. Harper Collin College Publishers, 1992.

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