Soars John & Hughes, S. (2019). Headway: Pre-intermediate Teacher's Guide (quinta edición.). Oxford University Press.
Citazione stile Chigago Style (17a edizione)Soars John e Stacy Hughes. Headway: Pre-intermediate Teacher's Guide. quinta edición. Oxford, United Kingdom: Oxford University Press, 2019.
Citatione MLA (9a ed.)Soars John e Stacy Hughes. Headway: Pre-intermediate Teacher's Guide. quinta edición. Oxford University Press, 2019.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.