Hafifuddin, Hafifuddin, and Ratna Tri Hari S. 2023. “Pengaruh Biaya Promosi Dan Margin Terhadap Jumlah Nasabah Bank Umum Syariah Periode 2015 - 2018”. Indonesian Journal of Economic and Business 1 (1):11-24. https://jurnal.pdpi.or.id/index.php/ijeb/article/view/4.