1. J. F. Elliott, J. F. Meikleham, and C. L. Kolbe:Energy Conversion for Space Power, Nathan W. Snyder, ed.,Progress in Astronautics and Rocketry, 1961, vol. 3, Academic Press, NY, pp. 263–73.
2. C. L. Kolbe: Report no. 63-RL-3221M, General Electric Research Laboratory, Schenectady, NY, 1963.
3. D. W. Lillie:Trans. TMS-A1ME, 1958, vol. 212, pp. 294–251.
4. H. Alexander and P. Haasen:Solid State Phys., 1968, vol. 22, pp. 27–158.
5. M. S. Abrahams:Trans. TMS-AIME, 1964, vol. 230, pp. 888–93.