Athikomkulchai, S., P. Vayumhasuwan, S. Tunvichien, S. Piyapong, S. Malaipuang, and N. Ruangrungsi. “The Development of Sunscreen Products from Kaempferia galanga”. Journal of Health Research, vol. 21, no. 4, Nov. 2018, pp. 253-6, https://he01.tci-thaijo.org/index.php/jhealthres/article/view/154181.