APA(7版)引用形式
Ruffin, R. J., & Gregory, P. R. (1990). Principles of economics (4th ed.). Scott, Foresman.
Chicagoスタイル(17版)引用形式
Ruffin, Roy J., , Paul R. Gregory. Principles of Economics. 4th ed. Glenview, Illinos: Scott, Foresman, 1990.
MLA(9版)引用形式
Ruffin, Roy J., , Paul R. Gregory. Principles of Economics. 4th ed. Scott, Foresman, 1990.
警告: この引用は必ずしも正確ではありません.