Dyfyniad APA
Samuelson, P. A., & Nordhaus, W. D. (2001). Economics (17th ed.). McGraw-Hill.
Dyfyniad Arddull Chicago
Samuelson, Paul A., and William D. Nordhaus. Economics. 17th ed. New York ; New Delhi: McGraw-Hill, 2001.
Dyfyniad MLA
Samuelson, Paul A., and William D. Nordhaus. Economics. 17th ed. McGraw-Hill, 2001.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.