APA (7th ed.) Zitazioa

Low, O. (1979). Certificate of proficiency English practice. Edward Arnold.

Chicago Style (17th ed.) Zitazioa

Low, Ona. Certificate of Proficiency English Practice. Londres: Edward Arnold, 1979.

MLA (9th ed.) Zitazioa

Low, Ona. Certificate of Proficiency English Practice. Edward Arnold, 1979.