Filip, Alina, and Lelia Voinea. 2012. “Understanding the Processes of Customer Acquisition, Customer Retention and Customer Relationship Development”. International Journal of Economic Practices and Theories 2 (2):62-67. http://inscriere.excelis.ase.ro/index.php/ijept/article/view/understanding_the_processes_of_customer_acquisition%2C_customer_.