Sulasmy W, Cahyaningtyas NW. Analisis Pengaruh Operating Expenses to Operating Income (Rasio Bopo), Cost Efficiency Ratio dan Non Performing Loan Terhadap Net Profit Margin Pada Perbankan di Bursa Efek Indonesia Periode Tahun 2015-2019. JK [Internet]. 2021Dec.31 [cited 2024May18];2(1):47-5. Available from: https://konsentrasi.upstegal.ac.id/index.php/Konsentrasi/article/view/23