1. P. A. Crossley, G. T. Noel, and M. Wolf, Final Report NASA AEDR3346, 1968.
2. A. L. Milnes and D. L. Feucht,Heterojunctions and Metal Semi-Conductor Junction(Academic, New York, 1972);
3. J. Lindmayer and C. Y. Wrigley,Fundamentals of Semiconductor Devices(Van Nostrand, Princeton, 1965);
4. and H. J. Hovel,Solar Cells in Semiconductors and Semimetals, edited by Willardson and Beer (Pergamon, New York, 1975).
5. Direct conversion of solar energy through photovoltaic cells