Joo, Jongwoo, and Yonghwan Lee. “A Proposal for Scientific Analysis on the Signboard Color of Gwanghwamoon”. International Journal of Engineering and Technology 7, no. 2.33 (June 8, 2018): 389–392. Accessed May 13, 2025. https://mail.sciencepubco.com/index.php/IJET/article/view/14192.