Haas, K. B. (1962). Professional salesmanship; persuasion and motivation in marketing. Holt, Rinehart and Winston.
Lua i Stíl Chicago (17ú heag.)Haas, Kenneth Brooks. Professional Salesmanship; Persuasion and Motivation in Marketing. New York: Holt, Rinehart and Winston, 1962.
Lua MLA (9ú heag.)Haas, Kenneth Brooks. Professional Salesmanship; Persuasion and Motivation in Marketing. Holt, Rinehart and Winston, 1962.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.