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