Singtongratana, Niramol, Sumontha Vadhanasin, and Jirada Singkhonrat. 2013. “Hydroxychavicol and Eugenol Profiling of Betel Leaves from Piper Betle L. Obtained by Liquid-Liquid Extraction and Supercritical Fluid Extraction”. Agriculture and Natural Resources 47 (4). Bangkok, Thailand:614-23. https://li01.tci-thaijo.org/index.php/anres/article/view/243103.