Buttle, F. (2009). Customer Relationship Management (7th.). Tata McGraw Hill.
Lua i Stíl Chicago (17ú heag.)Buttle, Francis. Customer Relationship Management. 7th. New Delhi: Tata McGraw Hill, 2009.
Lua MLA (9ú heag.)Buttle, Francis. Customer Relationship Management. 7th. Tata McGraw Hill, 2009.
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