Rakkarnngan, J. “Comparative hypotension effect between low dose and high dose crystalloid co-load in parturient under spinal anesthesia for elective cesarean section”. Journal of Preventive Medicine Association of Thailand, vol. 11, no. 3, Jan. 2022, pp. 641-52, https://he01.tci-thaijo.org/index.php/JPMAT/article/view/251598.