MM. (1991). Essentials Of Business Communication / Mary Ellen Guffey. PWS-Kent Publishing.
Chicago-viite (17. p.)MM. Essentials Of Business Communication / Mary Ellen Guffey. PWS-Kent Publishing, 1991.
MLA-viite (8. p.)MM. Essentials Of Business Communication / Mary Ellen Guffey. PWS-Kent Publishing, 1991.
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