1. J. V. Hall and A. Winer, Science, 255 (1992) 812.
2. M. Cone, Los Angeles Times, 9 May, 1996, A1.
3. California Thoracic Society, American Lung Association of California, October 1993, p. 5.
4. ONSI, Memo to Damberger, 9 July, 1996.
5. Gas Research Institute, Power Generation Tech. Update, May 1996, p. 5.