Winarto, W., Kamid, A. and Ramadhan, A. (2025) “Perhitungan Efisiensi Hydraulic Pumping Unit (HPU) pada Sumur yang Menggunakan Working Barrel Tipe Tubing Heavy Wall Barrel Mechanical PT. Pertamina Ep Cepu Regional 4 Zona 11 Cepu Field”, Ranah Research : Journal of Multidisciplinary Research and Development, 7(3), pp. 2217-2229. doi: 10.38035/rrj.v7i3.1612.