Cita APA (7a ed.)

Gude, K., & Duckworth, M. (2002). Proficiency masterclass: Exam practice workbook : with key : [Cassette]. Oxford University Press.

Cita Chicago Style (17a ed.)

Gude, Kathy, y Michael Duckworth. Proficiency Masterclass: Exam Practice Workbook : With Key : [Cassette]. Oxford: Oxford University Press, 2002.

Cita MLA (9a ed.)

Gude, Kathy, y Michael Duckworth. Proficiency Masterclass: Exam Practice Workbook : With Key : [Cassette]. Oxford University Press, 2002.