Gordman Robert. (2006). Must-Have Customer: 7 steps to winning the customer you haven't got. Truman Talley Books St.Martin Press.
Lua i Stíl Chicago (17ú heag.)Gordman Robert. Must-Have Customer: 7 Steps to Winning the Customer You Haven't Got. NewYork: Truman Talley Books St.Martin Press, 2006.
Lua MLA (9ú heag.)Gordman Robert. Must-Have Customer: 7 Steps to Winning the Customer You Haven't Got. Truman Talley Books St.Martin Press, 2006.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.