A.W, Z., I. A.F, and S. M.R. “Ultrafiltration of Natural Organic Matter (NOM): Effect of NOM Characteristics on Membrane Rejection Mechanisms in Drinking Water Process”. Malaysian Journal of Science, vol. 26, no. 1, Apr. 2007, pp. 97-107, http://mjs.um.edu.my/index.php/MJS/article/view/7979.