Zhang, Jianping, Chengxiang Chen, Wei Xie, Chaozhang Huang, Mingliang Su, Xiucai Liu, and Qixin Deng. 2012. “Regional Differentiation by Lead Isotope Ratios in Different Soil Fractions”. Asian Journal of Chemistry 25 (5):2435-37. https://doi.org/10.14233/ajchem.2013.13342.