Pfefferbaum, R. (1987). Economics: Study guide (2nd ed.). Houghton Mifflin.
Lua i Stíl Chicago (17ú heag.)Pfefferbaum, Rose. Economics: Study Guide. 2nd ed. Boston: Houghton Mifflin, 1987.
Lua MLA (9ú heag.)Pfefferbaum, Rose. Economics: Study Guide. 2nd ed. Houghton Mifflin, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.