Cita APA (7th ed.)
Oxenden, C. English file: Student's book (20a. ed.).
Cita Chicago (17th ed.)
Oxenden, Clive. English File: Student's Book. 20a. ed.
Cita MLA (9th ed.)
Oxenden, Clive. English File: Student's Book. 20a. ed.
Atenció: Aquestes cites poden no estar 100% correctes.