Oxenden, C. (2008). American English file: Workbook 4. Oxford: Oxford University.
Trích dẫn kiểu ChicagoOxenden, Clive. American English File: Workbook 4. Oxford: Oxford University, 2008.
Deismireacht MLAOxenden, Clive. American English File: Workbook 4. Oxford: Oxford University, 2008.
Rabhadh: D'fhéadfadh nach mbeadh na deismireachtaí seo 100% cruinn i gcónaí.