1. Jet Propulsion Laboratory, California Institute of Technology, Pasadena 91109
2. University of Kansas, Lawrence 66044
3. Johnson Space Flight Center, Houston, Texas 77058
4. University of Arkansas, Fayetteville 72701
5. Huntington Geology and Geophysics, London, England WD6 l5B
6. Chevron Oil Field Research, La Habra, California 90631