Faustina, Ega, and Sudradjat, Supijatno. 2015. “Optimization of Nitrogen and Phosphorus Fertilizer on Two Years Old of Oil Palm(<i>Elaeis Guineensis </I>Jacq.)”. Asian Journal of Applied Sciences 3 (3). https://www.ajouronline.com/index.php/AJAS/article/view/2669.