MM. (1991). Essentials Of Business Communication / Mary Ellen Guffey. PWS-Kent Publishing.
Lua i Stíl Chicago (17ú heag.)MM. Essentials Of Business Communication / Mary Ellen Guffey. PWS-Kent Publishing, 1991.
Lua MLA (8ú heag.)MM. Essentials Of Business Communication / Mary Ellen Guffey. PWS-Kent Publishing, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.