(1980). Persuasive communication / Erwin P. Bettinghaus.
Lua i Stíl Chicago (17ú heag.)Persuasive Communication / Erwin P. Bettinghaus. 1980.
Lua MLA (9ú heag.)Persuasive Communication / Erwin P. Bettinghaus. 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.