Cita APA

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

Chicago Style Citation

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

Cita MLA

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

Atenció: Aquestes cites poden no estar 100% correctes.