1. J. Hedström et al., 23rd IEEE Photov. Spec. Conf., IEEE, New York, 1993, pp. 364–367.
2. M. Ruckh, D. Schmid, M. Kaiser, R. Schäffler, T. Walter, H.W. Schock, 1st World Conf. Photov. Energy Conv., IEEE, New York, 1994, pp. 156–159.
3. M. Bodegård, L. Stolt, J. Hedström, in: R. Hill, W. Palz, P. Helm (Eds.), 12th Eur. Photov. Solar Energy Conf., Stephens, Bedford, 1994, pp. 236–239.