Hahner, J. C. (2002). Speaking Clearly: Improving voice and diction. New York: McGraw-Hill.
Παραπομπή Chicago StyleHahner, Jeffrey C. Speaking Clearly: Improving Voice and Diction. New York: McGraw-Hill, 2002.
Παραπομπή MLAHahner, Jeffrey C. Speaking Clearly: Improving Voice and Diction. New York: McGraw-Hill, 2002.
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