Cita APA (7a ed.)

Cunningham, S., & Bowler, B. (1990). Headway intermediate: Pronunciation. Oxford University Press.

Cita Chicago Style (17a ed.)

Cunningham, Sarah, y Bill Bowler. Headway Intermediate: Pronunciation. Oxford: Oxford University Press, 1990.

Cita MLA (8a ed.)

Cunningham, Sarah, y Bill Bowler. Headway Intermediate: Pronunciation. Oxford University Press, 1990.