AMAD, S., S. YUENYONGSAWAD, and C. WATTANAPIROMSAKUL. “Investigation of Antitubercular and Cytotoxic Activities of Fruit Extract and Isolated Compounds from Piper Retrofractum Vahl”. Walailak Journal of Science and Technology (WJST), vol. 14, no. 9, Aug. 2016, pp. 731-9, https://wjst.wu.ac.th/index.php/wjst/article/view/2190.