1. M.H. Acuña et al., Science 279, 1676–1680 (1998)
2. M.H. Acuña et al., Science 284, 790–793 (1999)
3. U.V. Amerstorfer, H. Lammer, T. Tokano, F. Selsis, C. Kolb, A. Bérces, G. Kovács, M.R. Patel, C.S. Cockell, Gy. Rontó, T. Penz, N.V. Erkaev, H.K. Biernat, in Proc. 3rd European Workshop on Exo/Astrobiology, ed. by R.A. Harris, L. Ouwehand. ESA SP, vol. 545 (2004), pp. 165–166
4. T.R. Ayres, J. Geophys. Res. 102, 1641–1651 (1997)
5. V.R. Baker, Nature 412, 228–236 (2001)