Air ionization at rock surface and pre-earthquake signals

Freund, F.T., I. Kulahci, G. Cyr, J. Ling, M. Winnick, J. Tregloan-Reed, and M.M. Freund (2009), Air ionization at rock surface and pre-earthquake signals, J. Atmos. Sol. Terr. Phys., 71, 1824-1834.