Rui, Yu-Kui, and Jing Hao. “Determination of Nine Heavy Metals by Inductively Coupled Plasma Mass Spectroscopy in Groundwater from Northeast Rural of China”. Asian Journal of Chemistry, vol. 24, no. 6, Feb. 2012, pp. 2825-6, https://asianpubs.org/index.php/ajchem/article/view/9239.