Nursamsiar, N. et al. 2023. The Effect of Extraction Method on Flavonoid Content and Antioxidant Activity of Red Betel and Green Betel Extracts: http://www.doi.org/10.26538/tjnpr/v7i8.7. Tropical Journal of Natural Product Research (TJNPR). 7, 8 (Aug. 2023), 3620–3625.