Tumanggor, A. H. U., A. Syarief, and F. A. Atmana. “The Damage Control of Liquid Waste Pumping Machines in Palm Oil Companies”. International Journal of Education, Science, Technology, and Engineering (IJESTE), Vol. 4, no. 2, Dec. 2021, pp. 59-73, doi:10.36079/lamintang.ijeste-0402.287.