Cita APA (7th ed.)

Guffey, M. E., & Seefer, C. M. (2007). Mary Ellen Guffey's essentials of business communication (7th ed.). Thomson/South-Western.

Cita Chicago (17th ed.)

Guffey, Mary Ellen, i Carolyn M. Seefer. Mary Ellen Guffey's Essentials of Business Communication. 7th ed. Mason, OH: Thomson/South-Western, 2007.

Cita MLA (9th ed.)

Guffey, Mary Ellen, i Carolyn M. Seefer. Mary Ellen Guffey's Essentials of Business Communication. 7th ed. Thomson/South-Western, 2007.