Scarpa, R., Amoruso, A., Crescentini, L., Fischione, C., Formisano, L. A., La Rocca, M. and Tronca, F. (2008) “Slow earthquakes and low frequency tremor along the Apennines, Italy”, Annals of Geophysics, 51(2-3). doi: 10.4401/ag-3028.