Adianingsih, Oktavia R., et al. “Validation of High-Performance Liquid Chromatography (HPLC) Method for Quantification of Ethyl P-Methoxycinnamate in Kaempferia Galanga Extract: Http: www.doi.org 10.26538 Tjnpr V7i8.39”. Tropical Journal of Natural Product Research (TJNPR), vol. 7, no. 8, Aug. 2023, pp. 3829-35, https://tjnpr.org/index.php/home/article/view/2459.