Hoang, Nguyen Van, Le Quang Dao, Dong Thu Van, and Pham Lan Hoa. “Heavy Metal Contamination of Soil Based on Pollution, Geo-Accumulation Indices and Enrichment Factor in Phan Me Coal Mine Area, Thai Nguyen Province, Vietnam”. <i>Vietnam Journal of Earth Sciences</i> 42, no. 2 (May 9, 2020): 105–117. Accessed November 8, 2025. http://vjes.vast.vn/jse/article/view/14950.