Cita APA (7th ed.)

Ruffin, R. J., & Gregory, P. R. (1993). Principles of macroeconomics (5th ed.). HarperCollins College Publishers.

Cita Chicago (17th ed.)

Ruffin, Roy J., i Paul R. Gregory. Principles of Macroeconomics. 5th ed. New York, N.Y: HarperCollins College Publishers, 1993.

Cita MLA (9th ed.)

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