1. McDonald, J. and Bennett, R.R., in NASA Conf. Publ., 1995, vol. 3298, report no. 95-31747, p. 3.
2. Lund, G.K., Spinti, J., and Doll, D.W., US Patent 5180452, 1993.
3. Symonds, R., Rose, W., and Reed, M., Nature, 1988, vol. 334, p. 415.
4. Sebacher, D.I., Bendura, R.J., and Wornom, D.E., Atmos. Environ., 1980, vol. 14, p. 543.
5. McEIroy, M. and Salawitch, R., Science, 1989, vol. 243, p. 763.