APA (7th ed.) Citation
Duckworth, M., & Gude, K. (1991). Success at First Certificate: Workbook. Oxford University Press.
Chicago Style (17th ed.) Citation
Duckworth, Michael, and Kathy Gude. Success at First Certificate: Workbook. Oxford: Oxford University Press, 1991.
MLA (9th ed.) Citation
Duckworth, Michael, and Kathy Gude. Success at First Certificate: Workbook. Oxford University Press, 1991.
Warning: These citations may not always be 100% accurate.