S. M. Dissanayake, I. R. Palihakkara, G. P. Gunaratna, and S. D. Wanniarachchi. “Effect of Different Levels of K on Growth Performance of Immature Oil Palm in Devithurai Estate Sri Lanka”. International Journal for Research in Applied Sciences and Biotechnology 6, no. 5 (September 30, 2019): 18-21. Accessed January 23, 2022. https://www.ijrasb.com/ojs/index.php/ojs-ijrasb/article/view/17.