Razi, F., H. Hendrayana, and A. Harijoko. “Identification and Distribution of Fluoride in Singkep Island, Lingga Regency, Riau Islands”. Journal of Degraded and Mining Lands Management, vol. 11, no. 4, July 2024, pp. 6185-99, doi:10.15243/jdmlm.2024.114.6185.