Wutthisas, J., C. Nateetorn, and A. Seesuk. “Concentrations of Radium-226 in Shawllow Well Waters and Bottled Waters in Surat Thani Province”. Journal of Health Science of Thailand, vol. 19, no. 6, Jan. 2018, pp. 921-9, https://thaidj.org/index.php/JHS/article/view/1550.