Samontha, Atitaya, and Thitipan Pinidanantachai. 2017. “Fractionation of Metals in Soil Surrounded Gold Mine at Phichit Province Using a Continuous-Flow Sequential Extraction”. Progress in Applied Science and Technology 7 (2). Thailand:111-19. https://ph02.tci-thaijo.org/index.php/past/article/view/243067.