Cita APA (7a ed.)

Soars, J., & Soars, L. (1987). Headway: Student's Book Upper-Intermediate (4th impression.). Oxford University Press.

Cita Chicago Style (17a ed.)

Soars, John, y Liz Soars. Headway: Student's Book Upper-Intermediate. 4th impression. Oxford: Oxford University Press, 1987.

Cita MLA (9a ed.)

Soars, John, y Liz Soars. Headway: Student's Book Upper-Intermediate. 4th impression. Oxford University Press, 1987.