Keivani, Meysam, and Nahavandi. “A Study of Customer Retention in Today’s Competitive World”. International Academic Journal of Business Management 1, no. 2 (December 30, 2014): 54–61. Accessed October 28, 2026. https://iaiest.com/iaj/index.php/IAJBM/article/view/IAJBM1410021.