APA (7th ed.) Citation

Ruffin, R. J. (1993). Principles of macroeconomics / Roy J. Ruffin, Paul R. Gregory (5th ed.). HarperCollins.

Chicago Style (17th ed.) Citation

Ruffin, Roy J. Principles of Macroeconomics / Roy J. Ruffin, Paul R. Gregory. 5th ed. New York: HarperCollins, 1993.

MLA (9th ed.) Citation

Ruffin, Roy J. Principles of Macroeconomics / Roy J. Ruffin, Paul R. Gregory. 5th ed. HarperCollins, 1993.