Sciarra, A., B. Cantucci, M. Buttinelli, G. Galli, M. Nazzari, L. Pizzino, and F. Quattrocchi. “Soil-Gas Survey of Liquefaction and Collapsed Caves During the Emilia Seismic Sequence”. Annals of Geophysics, vol. 55, no. 4, Oct. 2012, doi:10.4401/ag-6122.