Panjaitan, Hotman, and Djunaedi Djunaedi. “Product Advantage, Customer Relationship Marketing, and Service Quality on Customer Satisfaction of Bank Syariah Mandiri in Surabaya”. International Review of Management and Marketing, vol. 7, no. 4, Oct. 2017, pp. 122-30, https://econjournals.com/index.php/irmm/article/view/5170.