Ditthapornset, S., N. Lerkkasemsan, and S. Areerat. “Solvent Selection for Mitragynine Extraction by Hansen Solubility Parameter”. Engineering and Technology Horizons, vol. 40, no. 1, Mar. 2023, pp. 72-84, https://ph01.tci-thaijo.org/index.php/lej/article/view/249247.