Phattanaphakdee, Wattanaporn, et al. “Development and Validation of HPLC Method for Determination of Quercetin in Hydrogel Transdermal Patches Loaded With Red Onion Peel Extract: doi.org 10.26538 Tjnpr V6i8.8”. Tropical Journal of Natural Product Research (TJNPR), vol. 6, no. 8, Aug. 2022, pp. 1210-4, https://tjnpr.org/index.php/home/article/view/1289.