Eichler, A., G. Gramlich, T. Kellerhals, L. Tobler, T. Rehren, and M. Schwikowski. “Ice-Core Evidence of Earliest Extensive Copper Metallurgy in the Andes 2700 Years Ago: Highlights of Analytical Sciences in Switzerland”. CHIMIA, vol. 72, no. 3, Mar. 2018, p. 152, doi:10.2533/chimia.2018.152.