Mardhiyyah, Shola, et al. “Cytotoxic Activity of Xanthones from the Stem Bark of Cratoxylum Sumatranum: Http: www.doi.org 10.26538 Tjnpr V7i9.9”. Tropical Journal of Natural Product Research (TJNPR), vol. 7, no. 9, Oct. 2023, pp. 3908-10, https://www.tjnpr.org/index.php/home/article/view/2593.