Soars, L., & Soars, J. (2000). New headway: English course (1a. ed. 2a. reimp.). Oxford.

Soars, Liz, and John Soars. New Headway: English Course. 1a. ed. 2a. reimp. New York: Oxford, 2000.

Soars, Liz, and John Soars. New Headway: English Course. 1a. ed. 2a. reimp. Oxford, 2000.