Futrell, C. (1996). Fundamentals of selling: Customers for life (5th ed.). Irwin.
Lua i Stíl Chicago (17ú heag.)Futrell, Charles. Fundamentals of Selling: Customers for Life. 5th ed. Chicago: Irwin, 1996.
Lua MLA (8ú heag.)Futrell, Charles. Fundamentals of Selling: Customers for Life. 5th ed. Irwin, 1996.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.