Shurter, R. (1982). Effective letters in business. Tata Mc Graw Hill.
Lua i Stíl Chicago (17ú heag.)Shurter, Robert. Effective Letters in Business. New Delhi: Tata Mc Graw Hill, 1982.
Lua MLA (9ú heag.)Shurter, Robert. Effective Letters in Business. Tata Mc Graw Hill, 1982.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.