Citazione Stile APA (7a Edizione)
Soars, J., & Soars, L. (1994). Headway. Student's Book: Upper-Intermediate (17.impression.). Oxford University Press.
Citazione stile Chigago Style (17a edizione)
Soars, John, e Liz Soars. Headway. Student's Book: Upper-Intermediate. 17.impression. Oxford: Oxford University Press, 1994.
Citatione MLA (9a ed.)
Soars, John, e Liz Soars. Headway. Student's Book: Upper-Intermediate. 17.impression. Oxford University Press, 1994.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.