APA aipamena

An Official TOEFL Study Aid. (1989). Understanding TOEFL: Workbook. USA: Educational Testing Service.

Chicago Style aipamena

An Official TOEFL Study Aid. Understanding TOEFL: Workbook. USA: Educational Testing Service, 1989.

MLA aipamena

An Official TOEFL Study Aid. Understanding TOEFL: Workbook. USA: Educational Testing Service, 1989.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.