Dyfyniad APA

Samuelson, P. A., & Samuelson, W. (1980). Economics (11th ed.). McGraw-Hill.

Dyfyniad Arddull Chicago

Samuelson, Paul Anthony, and William Samuelson. Economics. 11th ed. New York: McGraw-Hill, 1980.

Dyfyniad MLA

Samuelson, Paul Anthony, and William Samuelson. Economics. 11th ed. McGraw-Hill, 1980.

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