M.H, Ng, Choo Y.M, Ma A.N, Chuah C.H, and Mohd. Ali Hashim. 2006. “Isolation and Identification of Individual Palm Carotenes Using Supercritical Fluid Chromatography”. Malaysian Journal of Science 25 (2):139-45. https://juku.um.edu.my/index.php/MJS/article/view/8147.