Anggana L, G., A. Himmawan DN, P. Hardiningsih, and S. Nawatmi. “PENINGKATAN PELAYANAN PELANGGAN PADA PERTAMINA ENDURO EXPRESS NITROGEN GO”. Jurnal Penamas, Vol. 7, no. 1, Feb. 2023, pp. 35 -40, https://www.unisbank.ac.id/ojs/index.php/penamas/article/view/9179.