Gallagher, N. (2004). Delta's key to the TOEFL test. Tp. Hồ Chí Minh: Trẻ.
Chicago ZitierstilGallagher, Nancy. Delta's Key to the TOEFL Test. Tp. Hồ Chí Minh: Trẻ, 2004.
MLA ZitierstilGallagher, Nancy. Delta's Key to the TOEFL Test. Tp. Hồ Chí Minh: Trẻ, 2004.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.