Soars, J. &. L., & Soars, L. (1991). Headway, Pre-Intermediate: Workbook. Oxford: Oxford University Press.
シカゴスタイル引用形Soars, John & Liz, , Liz Soars. Headway, Pre-Intermediate: Workbook. Oxford: Oxford University Press, 1991.
MLA引用形式Soars, John & Liz, , Liz Soars. Headway, Pre-Intermediate: Workbook. Oxford: Oxford University Press, 1991.
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