Norhanom, A., Y. Ashril , K Awang, and A. H. A. Hadi. “Protocol for Screening Cytotoxic Activity of Natural Products Against KB Cells”. Malaysian Journal of Science, vol. 18, no. 1, Apr. 1999, pp. 27-29, http://adum.um.edu.my/index.php/MJS/article/view/9377.