1. , , , , , , , , , and , Proc. 22nd IEEE Photovoltaic Specialists Conference, Las Vegas, NV, Vol. 1, 1254 (1991).
2. and , Energy Conversion and Utilization with High Efficiency, p. 141 (1990).
3. , , , , , and , Proc. 6th International Science and Engineering Conference (PVSEC-6), New Delhi, India, Oxford & IBH Publishing Co. PVT. Ltd., p. 753 (1992).
4. , , , and , Proc. 6th International Science and Engineering Conference (PVSEC-6), New Delhi, India, p. 463 (1992).