Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (9th ed.)

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