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), pp. 159-166. doi: 10.22302/iopri.jur.jpks.v29i3.153.