Tohutoro APA (7th ed.)

Hornby, A. Oxford Progressive English for Adult Learners. Oxford University Press.

Cita Chicago Style (17a ed.)

Hornby, A.S. Oxford Progressive English for Adult Learners. London: Oxford University Press.

Cita MLA (9a ed.)

Hornby, A.S. Oxford Progressive English for Adult Learners. Oxford University Press.