Pfefferbaum, R. (1987). Economics: Study guide (2nd ed.). Houghton Mifflin.
Dyfyniad Arddull ChicagoPfefferbaum, Rose. Economics: Study Guide. 2nd ed. Boston: Houghton Mifflin, 1987.
Dyfyniad MLAPfefferbaum, Rose. Economics: Study Guide. 2nd ed. Houghton Mifflin, 1987.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.