1. M.J. de Wild-Scholten, R. Glockner, J.-O. Odden, G. Halvorsen, and R. Tronstad: 23rd European Photovoltaic Solar Energy Conf., Valencia, Spain, 2008.
2. R. Kvande, L. Nygaard, S. Stute, and P.C.P. Bronsveld: 25th European Photovoltaic Solar Energy Conference and Exhibition/Conference on Photovoltaic Energy Conversion, Valencia, Spain, 2010.
3. K. Aasly: Ph.D. Dissertation, Norwegian University, Trondheim, Norway, 2008.
4. B. Strake, F.W. Schulze, and H.A. Aulich: Erzmetall, 1988, vol. 41, p. 126.
5. H.A. Aulich, H.-P.Urbach, F.W. Schulze, and J.G. Grabmaie: Siemens Forsch.-u Entwickl.-Ber. Bd., 1982, vol. 11, p. 327.