Zeter, Z. (2007). Sharpening skills for the TOEFL IBT: Four practice tests. Thành phố Hồ Chí Minh: Trẻ.
शिकागो स्टाइल उद्धरणZeter, Zeff. Sharpening Skills for the TOEFL IBT: Four Practice Tests. Thành phố Hồ Chí Minh: Trẻ, 2007.
एमएलए उद्धरणZeter, Zeff. Sharpening Skills for the TOEFL IBT: Four Practice Tests. Thành phố Hồ Chí Minh: Trẻ, 2007.
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