R. Dash, Pritesh, et al. “Friedelin Derivatives from Polygonum Flaccidum Showed Cytotoxic Activity on Vero Cell Line: doi.org 10.26538 Tjnpr V5i8.22”. Tropical Journal of Natural Product Research (TJNPR), vol. 5, no. 8, Aug. 2021, pp. 1456-9, https://tjnpr.org/index.php/home/article/view/467.