1. Laboratory of Comparative Carcinogenesis, National Cancer Institute, Frederick Cancer Research and Development Center, Frederick, MD 21702.
2. Food and Drug Administration, Rockville, MD 20852.
3. Food and Drug Administration, Washington, DC 20204.
4. PRI/DynCorp, NCI-FCRDC, Frederick, MD 21702.
5. Glaxo, Inc., Research Triangle Park, NC 27709.