Delang, Claudio O. “Heavy Metal Contamination of Soils in China: Standards, Geographic Distribution, and Food Safety Considerations. A Review”. DIE ERDE – Journal of the Geographical Society of Berlin 149, no. 4 (December 19, 2018): 261–268. Accessed June 14, 2024. https://www.die-erde.org/index.php/die-erde/article/view/397.