1. “Characterization of black volcanites from the Limay river basin, Patagonia, Argentina, using energy dispersive X-ray fluorescence spectrometry : an aid to infer human group mobility”. Palacios OM, van Meel K, Van Grieken R, Marcó P L-M, Vázquez C, Journal of radioanalytical and nuclear chemistry 298, 1245 (2013).   http://doi.org/10.1007/S10967-013-2600-1