Cita APA (7a ed.)

Soars, L., & Soars, J. (1998). New Headway English course: : upper-intermediate. Oxford University Press.

Cita Chicago Style (17a ed.)

Soars, Liz, y John Soars. New Headway English Course: : Upper-intermediate. Oxford: Oxford University Press, 1998.

Cita MLA (9a ed.)

Soars, Liz, y John Soars. New Headway English Course: : Upper-intermediate. Oxford University Press, 1998.