Soars, L., & Soars, J. (2011). New headway elementary student's book (4th ed.). Oxford University Press.

Soars, Liz, and John Soars. New Headway Elementary Student's Book. 4th ed. Oxford: Oxford University Press, 2011.

Soars, Liz, and John Soars. New Headway Elementary Student's Book. 4th ed. Oxford University Press, 2011.