APA (7th ed.) Zitazioa
Guffey, M. E. (1998). Essentials of business communication (4th ed.). South-Western College Pub..
Chicago Style (17th ed.) Zitazioa
Guffey, Mary Ellen. Essentials of Business Communication. 4th ed. Cincinnati, Ohio: South-Western College Pub., 1998.
MLA (9th ed.) Zitazioa
Guffey, Mary Ellen. Essentials of Business Communication. 4th ed. South-Western College Pub., 1998.
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