Dyfyniad APA

Amacher, R. C., & Ulbrich, H. H. (1995). Economic principles & policy (6th ed.). South-Western College.

Dyfyniad Arddull Chicago

Amacher, Ryan C., and Holley H. Ulbrich. Economic Principles & Policy. 6th ed. Cincinnati: South-Western College, 1995.

Dyfyniad MLA

Amacher, Ryan C., and Holley H. Ulbrich. Economic Principles & Policy. 6th ed. South-Western College, 1995.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.