1. Proc. 2nd World Conf. on Photov. Energy Conv;Schock,1998
2. Proc. 2nd World Conf. on Photov. Energy Conv;Hisamatsu,1998
3. M. Powalla, B. Dimmler, this issue.
4. A. Jasenek et al., in: Proc. of 16th European Photovoltaic Solar Energy Conf, in print.