1. Ahari, H., Bedard, R.L., Bowes, C.L., Coombs, N., Dag, O. et al. (1997), Nature, 388, 857.
2. A’Hearn, M.F. et al. (1995), Icarus, 118, 223.
3. Allamandola, J.M., Bernstein, M.P., Sandford, S.A. (1997), in Cosmovici, C.B., Bowyer, S. and Werthimer, D. (eds.), Astronomical and Biochemical Origins and the search for Life in the Universe, Editrice Compositori, p.23.
4. Bernstein, M.P., Sandford, S.A., Allamandola, L.J. (2000), ApJ, 542, 894.
5. Biver, N., Bockelée-Morvan, D., Crovisier, J., Henry, F., Davies, J.K. et al. (2000), AJ, 120, 1554.