Dyfyniad APA
Samuelson, P. A., & Nordhaus, W. D. (2006). Economics (18th ed. ( International ed.).). McGraw-Hill/Irwin.
Dyfyniad Arddull Chicago
Samuelson, Paul A., and William D. Nordhaus. Economics. 18th ed. ( International ed.). Boston: McGraw-Hill/Irwin, 2006.
Dyfyniad MLA
Samuelson, Paul A., and William D. Nordhaus. Economics. 18th ed. ( International ed.). McGraw-Hill/Irwin, 2006.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.