1. FRIEDMAN, J.D., U.S. GEOLOGICAL SURVEY TECHNICAL LETTER NASA-20 4 (1966).
2. Dellwig, L. F., Modern Geology: 63 (1969).
3. Dellwig, L. F., Modern Geology: 72 (1969).
4. Hoffer, R., Laboratory for Agriciultuiral Research Bulletin 844 68 (1968).
5. Analysis of rocks by spectral infrared emission (8 to 25 microns)