Dyfyniad APA

(2011). Natural resource and environmental economics. Harlow, Essex: Pearson Addison Wesley.

Dyfyniad Arddull Chicago

Natural Resource and Environmental Economics. Harlow, Essex: Pearson Addison Wesley, 2011.

Dyfyniad MLA

Natural Resource and Environmental Economics. Harlow, Essex: Pearson Addison Wesley, 2011.

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