Setiowati, R.D., Yenni, Y., Panjaitan, F.R., Sujadi, S., Irfan Lubis, M. and Ernayunita, E. 2021. Preliminary Study of Vitamin E Content in IOPRI’S Oil Palm Varieties. Jurnal Penelitian Kelapa Sawit. 29, 3 (Dec. 2021), 159-166. DOI:https://doi.org/10.22302/iopri.jur.jpks.v29i3.153.