Greenberg, P. (2010). CRM At the Speed of Light (4th.). Tata McGraw Hill.
Lua i Stíl Chicago (17ú heag.)Greenberg, Paul. CRM At the Speed of Light. 4th. Tata McGraw Hill, 2010.
Lua MLA (9ú heag.)Greenberg, Paul. CRM At the Speed of Light. 4th. Tata McGraw Hill, 2010.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.