1. University of Arizona, Tucson, AZ 85721
2. U.S. G.S., Flagstaff, AZ 86001
3. California Institute of Technology, Pasadena, CA 91125
4. New Mexico State University, Las Cruces, NM 88003
5. Vernadsky Institute for Cosmochemistry, USSR Academy of Science, Moscow
6. Jet Propulsion Laboratory, Pasadena, CA 91109
7. NASA Headquarters, Washington, DC 20546
8. Observatoire de Paris, Meudon, Paris, France
9. Cornell University, Ithaca, NY 14853
10. Corporation, Santa Monica, CA 90406
11. Center for Astrophysics, Cambridge, MA 02138
12. NASA Ames Research Center, Moffett Field, CA 94035
13. Rand Corporation, Santa Monica, CA 90406
14. University of Toronto, Toronto, Ontario M5S 1A1, Canada
15. National Optical Astronomy Observatories, Tucson, AZ 85726
16. Logica International, Ltd., 64 Neisman Street, London, England W1A 4SE
17. University of Wisconsin, Madison, WI 53706
18. State University of New York, Stony Brook, NY 11794
19. Mycol, Inc., Sunnyvale, CA 94087
20. Stanford University, Stanford, CA 94305
21. Institute for Astronomy, University of Hawaii, Honolulu, HI 95822