ELLYNIA, Ellynia; TJHIN, Viany Utami. Penerapan Customer Relationship Management (CRM) pada Aplikasi Pengiriman Pesan Instan Studi Kasus: WhatsApp, WeChat, Line, KakaoTalk. Ultima InfoSys : Jurnal Ilmu Sistem Informasi, [S. l.], v. 5, n. 1, p. 20–26, 2014. DOI: 10.31937/si.v5i1.215. Disponível em: https://ejournals.umn.ac.id/index.php/SI/article/view/215. Acesso em: 11 aug. 2025.