Dyfyniad APA

Gregory, P. R. (2005). Essentials of economics. Boston, MA: Pearson Education.

Dyfyniad Arddull Chicago

Gregory, Paul R. Essentials of Economics. Boston, MA: Pearson Education, 2005.

Dyfyniad MLA

Gregory, Paul R. Essentials of Economics. Boston, MA: Pearson Education, 2005.

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