Ng, W. K. ; Lim, H. A. ; Lim, S. L. ; Ibrahim, C. O., 2002. Nutritive value of palm kernel meal pretreated with enzyme or fermented with Trichoderma koningii (Oudemans) as a dietary ingredient for red hybrid tilapia (Oreochromis sp.). Aquacult. Res., 33: 1199-1207