Cita APA (7a ed.)

Duckworth, M. (1999). First class: English for tourism. Workbook. Oxford University Press.

Cita Chicago Style (17a ed.)

Duckworth, Michael. First Class: English for Tourism. Workbook. Oxford: Oxford University Press, 1999.

Cita MLA (8a ed.)

Duckworth, Michael. First Class: English for Tourism. Workbook. Oxford University Press, 1999.