M. F. Atan, K.A. Mapi, S. N. F. Ghazali, N. Abdul Rahman, and S. F. Salleh. “Utilization of Coconut Copra As Low Cost Biosorbents for Removal of Humic Substances from Peat Swamp Run-Off”. Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, vol. 3, no. 1, Nov. 2014, pp. 6-16, https://semarakilmu.com.my/journals/index.php/fluid_mechanics_thermal_sciences/article/view/2527.