Michael Duckworth, & Michael Duckworth; Kathy Gude. (1999). Countdown to first certificate: Workbook : with key and tapescripts. Oxford: Oxford University Press.
シカゴスタイル引用形Michael Duckworth, , Michael Duckworth; Kathy Gude. Countdown to First Certificate: Workbook : With Key and Tapescripts. Oxford: Oxford University Press, 1999.
MLA引用形式Michael Duckworth, , Michael Duckworth; Kathy Gude. Countdown to First Certificate: Workbook : With Key and Tapescripts. Oxford: Oxford University Press, 1999.
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