APA (7th ed.) Zitazioa
Guffey, M. E. (1991). Essentials of business communication. Mason, OH.
Chicago Style (17th ed.) Zitazioa
Guffey, Mary E. Essentials of Business Communication. London: Mason, OH, 1991.
MLA (9th ed.) Zitazioa
Guffey, Mary E. Essentials of Business Communication. Mason, OH, 1991.
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