Foihirun, Kamon, Varaporn Cholumpai, Angkana Kritpitakngern, Jiraporn Umpunh, Warrasak Inchai, and Parichat Sukpeng. 2019. “Laboratory Examination for Narcotic Drugs and Psychotropic Substances Used Among Drug Users in Thailand”. Journal of Health Science of Thailand 15 (1):94-101. https://thaidj.org/index.php/JHS/article/view/6720.