Yunimar, Yunimar, Zakaria Aziz, and Adi Prawira. “UPAYA COSTUMER SERVICE BANK SYARIAH BUKOPIN CABANG PEMBANTU PAYAKUMBUH DALAM MELAYANI KELUHAN NASABAH ”. El-kahfi | Journal of Islamic Economics 1, no. 01 (March 6, 2020): 1-8. Accessed July 4, 2025. https://ejournal.mannawasalwa.ac.id/index.php/elkahfi/article/view/25.