APA (7th ed.) Citation

Oxford University Press, Soars, J., & Soars, L. (1991). Headway: Pre-intermediate student's book. Oxford University Press.

Chicago Style (17th ed.) Citation

Oxford University Press, J. Soars, and L. Soars. Headway: Pre-intermediate Student's Book. [χ.τ.]: Oxford University Press, 1991.

MLA (8th ed.) Citation

Oxford University Press, et al. Headway: Pre-intermediate Student's Book. Oxford University Press, 1991.