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, Vol. 6, no. 5, Sept. 2019, pp. 18-21, doi:10.31033/ijrasb.6.5.3.