Lougheed, L. (2011). Ielts International English Languages Testing System. Nhân Trí Việt.
Chicago Style aipamenaLougheed, Lin. Ielts International English Languages Testing System. Nhân Trí Việt, 2011.
MLA aipamenaLougheed, Lin. Ielts International English Languages Testing System. Nhân Trí Việt, 2011.
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