Ussanawarong, S., and K. Chirasirisap. “Study of Enzyme Cholinesterase Levels of Farmers in Kud – Kwang village”. Srinagarind Medical Journal, vol. 8, no. 4, Nov. 2013, pp. 215-9, https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/13662.