Yusmansyah , E.F. , Martinis, S. , Sulyani , A.C. , Nurhasanah, H. and Rivianto, R.D.W. 2023. Measuring Internal Customer Satisfaction Using Net Promoter Score: Case Study on Digital Product. International Journal of Membrane Science and Technology. 10, 2 (Aug. 2023), 3089-3097. DOI:https://doi.org/10.15379/ijmst.v10i2.3053.