Hersey, P. (1988). Selling: A behavioral science approach. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Hersey, Paul. Selling: A Behavioral Science Approach. Englewood Cliffs, N.J: Prentice-Hall, 1988.
Lua MLA (9ú heag.)Hersey, Paul. Selling: A Behavioral Science Approach. Prentice-Hall, 1988.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.