Cita APA (7th ed.)
Hornby, A. S. (1967). Oxford progressive english alternative course. Oxford University Press.
Cita Chicago (17th ed.)
Hornby, A. S. Oxford Progressive English Alternative Course. London: Oxford University Press, 1967.
Cita MLA (9th ed.)
Hornby, A. S. Oxford Progressive English Alternative Course. Oxford University Press, 1967.
Atenció: Aquestes cites poden no estar 100% correctes.