Mi-suk Kim, and Jeon, Sang-wan Jeon. “Operation and Achievements of Permanent Referee System in Korea for Establishment of Fairness in Korean Sports Referee Culture”. Elementary Education Online, vol. 20, no. 3, Dec. 2023, pp. 1127-35, https://ilkogretim-online.org/index.php/pub/article/view/1982.