SANGKHARAK, K., PICHID, N., YUNU, T. and KINGMAN, P. 2016. Separation of Carotenes and Vitamin E from Palm Oil Mill Effluent Using Silica from Agricultural Waste as an Adsorbent. Walailak Journal of Science and Technology (WJST). 13, 11 (Jan. 2016), 939–947.