Saru, Putri, Vera A.R Pasaribu, and Jonson Rajagukguk. “Analisis Strategi Peningkatan Kepuasan Pelanggan Di PT Kereta Api Indonesia Dirve 1 Sumatera Utara”. Journal of Laguna Geography 4, no. 1 (April 9, 2025): 26-30. Accessed October 12, 2025. https://journal.moripublishing.com/index.php/joulage/article/view/1538.