Afrillah, M., C. Hanum, and A. Rauf. “Efficiency Use of Nitrogen In Several Palm Oil Varieties With Treatment of Nitrogen Fertilizer Levels In Main Nursery”. Jurnal Online Pertanian Tropik, vol. 5, no. 3, 1, pp. 428- 433, doi:10.32734/jopt.v5i3.3116.