Rizky F, Sudiarti S, Atika. Strategi Costumer Relationship Management Dalam Mempertahankan Pelanggan Pada Coffee Shop Grama Sphere. ef [Internet]. 2023 Oct. 10 [cited 2024 Dec. 4];5(3):247-59. Available from: https://jurnal.kdi.or.id/index.php/ef/article/view/951