Buttle, F. (2004). Customer Relationship Management. Elsevier.
Lua i Stíl Chicago (17ú heag.)Buttle, Francis. Customer Relationship Management. New Delhi: Elsevier, 2004.
Lua MLA (9ú heag.)Buttle, Francis. Customer Relationship Management. Elsevier, 2004.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.