Kayunkid, O. “Applying LEAN Concepts to Improve Quality of Outpatient Care: Case Study from Bhumibol Adulyadej Hospital”. Royal Thai Air Force Medical Gazette, vol. 69, no. 1, Aug. 2023, pp. 1-9, https://he02.tci-thaijo.org/index.php/rtafmg/article/view/262899.