Dyfyniad APA

Byrns, R. T., & Stone, G. W. (1989). Economics (4th ed.). Scott, Foresman.

Dyfyniad Arddull Chicago

Byrns, Ralph T., and Gerald W. Stone. Economics. 4th ed. Glenview, Ill.: Scott, Foresman, 1989.

Dyfyniad MLA

Byrns, Ralph T., and Gerald W. Stone. Economics. 4th ed. Scott, Foresman, 1989.

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