Soars, J., & Soars, L. (2009). New Headway: Upper-Intermediate : Teacher's Book (3a. ed.). Oxford University Press.

Soars, John, and Liz Soars. New Headway: Upper-Intermediate : Teacher's Book. 3a. ed. New York: Oxford University Press, 2009.

Soars, John, and Liz Soars. New Headway: Upper-Intermediate : Teacher's Book. 3a. ed. Oxford University Press, 2009.