Physicochemical or geochemical

• Brogna, A., La Delfa, S., La Monaca, V., Lo Nigro, S., Morelli, D., Patane, G., Tringali, G., (2007), Measurements of indoor radon concentration on the south-eastern flank of Mount Etna volcano (Southern Italy), Journal of Volcanology and Geothermal Research, 165(1-2), 71-75, 10.1016/j.jvolgeores.2007.04.012