Dyfyniad APA

Samuelson, P., & Nordhaus, W. (2015). Economics (19th ed.). McGraw Hill.

Dyfyniad Arddull Chicago

Samuelson, Paul, and William Nordhaus. Economics. 19th ed. INDIA: McGraw Hill, 2015.

Dyfyniad MLA

Samuelson, Paul, and William Nordhaus. Economics. 19th ed. McGraw Hill, 2015.

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