Flem, B., Reimann, C., Fabian, K., Birke, M., Filzmoser, P., & Banks, D. (2018). Graphical statistics to explore the natural and anthropogenic processes influencing the inorganic quality of drinking water, ground water and surface water. Applied Geochemistry, 88, 133–148. https://doi.org/10.1016/j.apgeochem.2017.09.006