Somma, R., Gianfrani, L., Gagliardi, G., De Natale, G., De Natale, P., Rocco, A., Tedesco, D., Zimmer, M. (2005): Preliminary results of continuous gas geochemical monitoring at Solfatara volcano (Campi Flegrei) southern Italy, 2nd General Assembly European Geosciences Union (Vienna, Austria 2005).