APA (7th ed.) Zitazioa
Beardshaw, J. (1998). Economics: A student's guide (4th ed.). PEL.
Chicago Style (17th ed.) Zitazioa
Beardshaw, John. Economics: A Student's Guide. 4th ed. New York: PEL, 1998.
MLA (9th ed.) Zitazioa
Beardshaw, John. Economics: A Student's Guide. 4th ed. PEL, 1998.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.