Ur, P., & Penny Ur. (1988). Grammar practice activities: A practical guide for teachers. Cambridge,New York: Cambridge University Press.
Παραπομπή Chicago StyleUr, Penny, και Penny Ur. Grammar Practice Activities: A Practical Guide for Teachers. Cambridge,New York: Cambridge University Press, 1988.
Παραπομπή MLAUr, Penny, και Penny Ur. Grammar Practice Activities: A Practical Guide for Teachers. Cambridge,New York: Cambridge University Press, 1988.
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