Watkins, D. E., & De Bower, H. F. (1927). Effective speech: Including mental training and the development of personality. New York: The De Bower Publishing.
Παραπομπή Chicago StyleWatkins, Dwight Everett, και Herbert Francis De Bower. Effective Speech: Including Mental Training and the Development of Personality. New York: The De Bower Publishing, 1927.
Παραπομπή MLAWatkins, Dwight Everett, και Herbert Francis De Bower. Effective Speech: Including Mental Training and the Development of Personality. New York: The De Bower Publishing, 1927.
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