636 THE BELL SYSTEM TECHNICAL JOURNAL, MAY 1956 



66. Shockley, W., Electrons and Holes in Semiconductors, Chapter 8, Van Nos- 



trand, 1950. 



67. Shockley, W., Electrons and Holes in Semiconductors, Chapter 16, Van Nos- 



trand, 1950. 



68. Geballe, T. H., and Morin, F. J., Phys. Rev., 95, p. 1085, 1954. 



69. Conant,J. B., The Chemistry of OrganicCompounds,p. 196,Macmillan, 1939. 



70. Valenta, M., and Ramasastry, C, Symposium on Semiconductors, Meeting 



I.M.D., and A.I.M.E., Feb. 20, 1956. 



71. Longini, R. E., and Green, R., Phys. Rev. (in press). 



I 



