Παραπομπή APA

Duckworth, M., & Michael Duckworth; Kathy Gude. (1999). Countdown to First Certificate: Workbook with key and tapescripts. Oxford: Oxford University Press.

Παραπομπή Chicago Style

Duckworth, Michael, και Michael Duckworth; Kathy Gude. Countdown to First Certificate: Workbook With Key and Tapescripts. Oxford: Oxford University Press, 1999.

Παραπομπή MLA

Duckworth, Michael, και Michael Duckworth; Kathy Gude. Countdown to First Certificate: Workbook With Key and Tapescripts. Oxford: Oxford University Press, 1999.

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