Jaya Putra, Rizki, and Elke Alexandrina. “Relationship Marketing on Loyal Customer: A Descriptive Study of Total Bangun Persada’s Customer Care Department”. Ultimacomm: Jurnal Ilmu Komunikasi, vol. 11, no. 1, June 2019, pp. 53-68, doi:10.31937/ultimacomm.v11i1.1169.