APA(7版)引用形式

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

Chicagoスタイル(17版)引用形式

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

MLA(9版)引用形式

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

警告: この引用は必ずしも正確ではありません.