Samuelson, P. A. (1992). Economics. New York: McGraw-Hill.
Dyfyniad Arddull ChicagoSamuelson, Paul Anthony. Economics. New York: McGraw-Hill, 1992.
Dyfyniad MLASamuelson, Paul Anthony. Economics. New York: McGraw-Hill, 1992.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.