Setiowati, Retno Diah, Yurna Yenni, Frisda Rimbun Panjaitan, Sujadi Sujadi, Mahmud Irfan Lubis, and Ernayunita Ernayunita. 2021. “Preliminary Study of Vitamin E Content in IOPRI’S Oil Palm Varieties”. Jurnal Penelitian Kelapa Sawit 29 (3), 159-66. https://doi.org/10.22302/iopri.jur.jpks.v29i3.153.