APA način citiranja (7. izdanje)

Gregory, P. R., & Ruffin, R. J. (1993). Principles of economics (5th ed.). Harper Collins College.

Čikaški stil citiranja (17. izdanje)

Gregory, Paul R., i Roy J. Ruffin. Principles of Economics. 5th ed. New York: Harper Collins College, 1993.

MLA način citiranja (9. izdanje)

Gregory, Paul R., i Roy J. Ruffin. Principles of Economics. 5th ed. Harper Collins College, 1993.