APA (7th ed.) Citation
Ruffin, R. J., & Gregory, P. R. (1993). Principles of Economics (5th Edition.). Harper Collins College Publishers.
Chicago Style (17th ed.) Citation
Ruffin, Roy J., and Paul R. Gregory. Principles of Economics. 5th Edition. New York: Harper Collins College Publishers, 1993.
MLA (9th ed.) Citation
Ruffin, Roy J., and Paul R. Gregory. Principles of Economics. 5th Edition. Harper Collins College Publishers, 1993.
Warning: These citations may not always be 100% accurate.