Sharpe, P. J. (2006). Pass key to the TOEFL iBT: Test of English as a foreign language : Internet-based test. Thành phố Hồ Chí Minh: Trẻ.
Παραπομπή Chicago StyleSharpe, Pamela J. Pass Key to the TOEFL IBT: Test of English As a Foreign Language : Internet-based Test. Thành phố Hồ Chí Minh: Trẻ, 2006.
Παραπομπή MLASharpe, Pamela J. Pass Key to the TOEFL IBT: Test of English As a Foreign Language : Internet-based Test. Thành phố Hồ Chí Minh: Trẻ, 2006.
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