1. Aki, K., Richards, P.G., 1980. Quantitative Seismology, W.H. Freeman, New York.
2. Benites, R., Haines, A.J., 1994. Quantification of Seismic Wavefield Amplification by Topographic Features. Client Report 343901, Intitute of Geological and Nuclear Sciences, 108 pp.
3. Shear-wave polarizations on a curved wavefront at an isotropic free surface;Booth;Geophys. J. Int.,1985
4. Long-period volcano seismicity: its source and use in eruption forecasting;Chouet;Nature,1996
5. Unusual low-frequency volcanic seismic events with slowly decaying coda waves observed at Galeras and other volcanoes;Gómez;J. Volcanol. Geotherm. Res.,1997