APA aipamena

Educational Testing Service. (2021). The official guide to the Toefl IBT test (6th ed.). New York: McGraw Hill.

Chicago Style aipamena

Educational Testing Service. The Official Guide to the Toefl IBT Test. 6th ed. New York: McGraw Hill, 2021.

MLA aipamena

Educational Testing Service. The Official Guide to the Toefl IBT Test. 6th ed. New York: McGraw Hill, 2021.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.