Tan, S. X., N. N. Basri, and K. Zainol Abidin. “Challenges in Managing Plasma Cell Gingivitis Associated With Copper Sulphate: A Case Report”. Mahidol Dental Journal, vol. 42, no. 3, Dec. 2022, pp. 223-30, https://he02.tci-thaijo.org/index.php/mdentjournal/article/view/259003.