Cita APA

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

Citación estilo Chicago

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

Cita MLA

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