Fajrin Harahap, M., R. Amanda Lubis, A. Nurmi, and D. Erwin Harahap. “Metal Content Of Midrib Sap Flour Salak Tree (Tgps) As A Thickening Agent”. International Journal of Science, Technology & Management, Vol. 4, no. 5, Sept. 2023, pp. 1288-93, doi:10.46729/ijstm.v4i5.908.