WASET
    K. Liagkouras and  K. Metaxiotis,  Application of Customer Relationship Management Systems in Business: Challenges and Opportunities.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    May 2014, vol. 90(6). 1642 - 1646
    [viewed 28 March 2024]. Available from: https://publications.waset.org/pdf/9998370.