1. P. R. Thornton, “Scanning Electron Microscopy” (Chapman and Hall, London, 1968).
2. P. W. Mcmillan, “Glass Ceramics” (Academic Press, 1964).
3. C. W. Price andD. W. Johnson, 4th Annual Scanning Electron Microscope Symposium, IIT Research Institute, Chicago (1971) p. 145.
4. D. H. Krinsley andP. J. W. Hyde,ibid., p. 409.
5. R. F. Sippel andA. B. Spencer,Proc. Apollo 11 Lunar Science Cong. 3 (1970) 2413.