Elfenbein, J. (1973). Business letters and communication. Alexander hamilton Inc.
Lua i Stíl Chicago (17ú heag.)Elfenbein, Julien. Business Letters and Communication. New York: Alexander hamilton Inc, 1973.
Lua MLA (9ú heag.)Elfenbein, Julien. Business Letters and Communication. Alexander hamilton Inc, 1973.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.