Utari, R. E., & Andah, B. D. (2018). PENGARUH PENERAPAN ELECTRONIC CUSTOMER RELATIONSHIP MANAGEMENT TERHADAP UPAYA PENINGKATAN LOYALITAS WALI MURID SMK MUHAMMADIYAH 9 JAKARTA. IDEALIS : InDonEsiA JournaL Information System, 1(3), 390–395. Retrieved from https://jom.fti.budiluhur.ac.id/IDEALIS/article/view/1276