Soars, J., & Soars, L. (1987). Headway upper - intermediate: Student's Book. New York: Oxford University Press.
Παραπομπή Chicago StyleSoars, John, και Liz Soars. Headway Upper - Intermediate: Student's Book. New York: Oxford University Press, 1987.
Παραπομπή MLASoars, John, και Liz Soars. Headway Upper - Intermediate: Student's Book. New York: Oxford University Press, 1987.
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