Joo, Jongwoo, and Yonghwan Lee. “A Proposal for Scientific Analysis on the Signboard Color of Gwanghwamoon”. International Journal of Engineering & Technology 7, no. 3.24 (August 10, 2018): 600–604. Accessed May 2, 2024. https://sciencepubco.com/index.php/ijet/article/view/22823.